/*
 * International Chemical Identifier (InChI)
 * Version 1
 * Software version 1.02
 * October 31, 2008
 * Developed at NIST
 *
 * The InChI library and programs are free software developed under the
 * auspices of the International Union of Pure and Applied Chemistry (IUPAC);
 * you can redistribute this software and/or modify it under the terms of 
 * the GNU Lesser General Public License as published by the Free Software 
 * Foundation:
 * http://www.opensource.org/licenses/lgpl-license.php
 */


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "mode.h"

#include "inpdef.h"
#include "ichi.h"
#include "strutil.h"
#include "util.h"
#include "extr_ct.h"
#include "ichitaut.h"
#include "ichinorm.h"
#include "ichicant.h"
#include "ichicano.h"
#include "ichicomn.h"

#include "ichicomp.h"
#include "ichimain.h"
#include "ichimake.h"


/***************************************************************************/
int str_Sp2(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI,  *pINChI_Prev,  *pINChI_Taut,  *pINChI_Taut_Prev;
    INChI_Stereo *Stereo, *Stereo_Prev, *Stereo_Taut, *Stereo_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        

    pINChI_Taut      = NULL;
    pINChI_Prev      = NULL;
    pINChI_Taut_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero only on the 2nd (non-taut) pass */
    eq2tautPrev = 1; /* pINChI_Prev (previous pINChI) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*================ compare sp2 to previous =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI[ii2] : NULL;
        }
        /*========= if bSecondNonTautPass then compare non-iso non-taut stereo to non-iso taut ========*/
        eq2taut = 0;
#if ( FIX_EMPTY_LAYER_BUG == 1 )
        if ( !eq2taut && bSecondNonTautPass && bOmitRepetitions && pINChI && pINChI_Taut ) {
            Stereo = pINChI->Stereo;
            Stereo_Taut = pINChI_Taut->Stereo;
            eq2taut = Stereo && Stereo_Taut &&
                      Eql_INChI_Stereo( Stereo, EQL_SP2, Stereo_Taut, EQL_SP2, 0 );
            eq2taut = eq2taut? (iiSTEREO | iitNONTAUT) : 0;

            if ( !eq2taut &&
                 !Eql_INChI_Stereo( Stereo, EQL_SP2, NULL, EQL_EXISTS, 0 ) &&
                  Eql_INChI_Stereo( Stereo_Taut, EQL_SP2, NULL, EQL_EXISTS, 0 ) ) {
                eq2taut = iiEmpty; /* the current is empty while the preceding (taut) is not */
            }
        }
#else
        if ( !eq2taut && bSecondNonTautPass && bOmitRepetitions ) {
            eq2taut = pINChI && pINChI_Taut &&
                      (Stereo = pINChI->Stereo) && (Stereo_Taut = pINChI_Taut->Stereo) &&
                      Eql_INChI_Stereo( Stereo, EQL_SP2, Stereo_Taut, EQL_SP2, 0 );
            eq2taut = eq2taut? (iiSTEREO | iitNONTAUT) : 0;
        }
#endif
        if ( eq2taut ) {
            /* we may be here only in case of the second (non-taut) pass */
            /* current non-taut stereo has been found to be same as tautomeric */
            if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                /* previous component exists; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( (Stereo_Prev = pINChI_Prev->Stereo) && Stereo_Prev->nNumberOfStereoBonds > 0 ) {
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                    tot_len += MakeStereoString( Stereo_Prev->nBondAtom1, Stereo_Prev->nBondAtom2,
                                                 Stereo_Prev->b_parity,
                                                 0, Stereo_Prev->nNumberOfStereoBonds,
                                                 pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                }
            } else
            if ( pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
            }
            /* we have found pINChI->Stereo sp2 same as in pINChI_Taut */
            /* output this (current) equivalence as '*', that is, same as tautomeric */
            /* that was printed on the 1st pass. */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output the previous one */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
            pINChI_Prev      = NULL; /* pINChI_Prev sp2 does not exist since */
            pINChI_Taut_Prev = NULL; /* pINChI has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;     /* pINChI_Prev sp2 does not exist */
        } else 
        if ( eq2tautPrev ) {
            /* at this point pINChI_Prev does not exist; however, pINChI */
             /*might have been discovered and it is different from pINChI_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Prev      = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0;
        } else {
            /* check whether pINChI and pINChI_Prev have non-zero identical stereo sp2 */
            eq2prev =bUseMulipliers &&
                     pINChI && pINChI_Prev &&
                     (Stereo = pINChI->Stereo) && (Stereo_Prev = pINChI_Prev->Stereo) &&
                     Eql_INChI_Stereo( Stereo, EQL_SP2, Stereo_Prev, EQL_SP2, 0 );
            if ( eq2prev ) {
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                /* pINChI sp2 info is either different or trivial. Output pINChI_Prev anyway */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                    if ( (Stereo_Prev = pINChI_Prev->Stereo) && Stereo_Prev->nNumberOfStereoBonds > 0 ) {
                        /* pINChI_Prev exists and has sp2 info */
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                        tot_len += MakeStereoString( Stereo_Prev->nBondAtom1, Stereo_Prev->nBondAtom2,
                                                     Stereo_Prev->b_parity,
                                                     0, Stereo_Prev->nNumberOfStereoBonds,
                                                     pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                    }
                    /* else sp2 info is not present in pINChI_Prev */
                } else
                if ( bSecondNonTautPass && pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                     if ( (Stereo_Taut_Prev = pINChI_Taut_Prev->Stereo) && Stereo_Taut_Prev->nNumberOfStereoBonds > 0 ) {
                        /* since pINChI_Prev does not exist, pINChI_Taut_Prev is non-tautomeric */
                        /* and it has non-trivial sp2 info */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                        ;/* pINChI_Taut_Prev sp2 info was output in the main stereo section */
                     } else {
                        ; /* pINChI_Taut_Prev exists and has not sp2 info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Prev = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}

/***************************************************************************/
int str_Sp3(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components, int bRelRac,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI,  *pINChI_Prev,  *pINChI_Taut,  *pINChI_Taut_Prev;
    INChI_Stereo *Stereo, *Stereo_Prev, *Stereo_Taut, *Stereo_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    pINChI_Taut      = NULL;
    pINChI_Prev      = NULL;
    pINChI_Taut_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero only on the 2nd (non-taut) pass */
    eq2tautPrev = 1; /* pINChI_Prev (previous pINChI) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
#if( REL_RAC_STEREO_IGN_1_SC == 1 )
#else
    bRelRac = 0;
#endif
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*================ compare sp3 to previous =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI[ii2] : NULL;
        }
        /*========= if bSecondNonTautPass then compare non-iso non-taut stereo to non-iso taut ========*/
        eq2taut = 0;
#if ( FIX_EMPTY_LAYER_BUG == 1 )
        if ( !eq2taut && bSecondNonTautPass && bOmitRepetitions && pINChI && pINChI_Taut ) {
            Stereo = pINChI->Stereo;
            Stereo_Taut = pINChI_Taut->Stereo;
            eq2taut = Stereo && Stereo_Taut &&
                      Eql_INChI_Stereo( Stereo, EQL_SP3, Stereo_Taut, EQL_SP3, bRelRac );
            eq2taut = eq2taut? (iiSTEREO | iitNONTAUT) : 0;
            if ( !eq2taut &&
                 !Eql_INChI_Stereo( Stereo, EQL_SP3, NULL, EQL_EXISTS, 0 ) &&
                  Eql_INChI_Stereo( Stereo_Taut, EQL_SP3, NULL, EQL_EXISTS, 0 ) ) {
                eq2taut = iiEmpty; /* the current is empty while the preceding (taut) is not */
            }
        }
#else
        if ( !eq2taut && bSecondNonTautPass && bOmitRepetitions ) {
            eq2taut = pINChI && pINChI_Taut &&
                      (Stereo = pINChI->Stereo) && (Stereo_Taut = pINChI_Taut->Stereo) &&
                      Eql_INChI_Stereo( Stereo, EQL_SP3, Stereo_Taut, EQL_SP3, bRelRac );
            eq2taut = eq2taut? (iiSTEREO | iitNONTAUT) : 0;
        }
#endif
        if ( eq2taut ) {
            /* we may be here only in case of the second (non-taut) pass */
            /* current non-taut stereo has been found to be same as tautomeric */
            if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                /* previous component exists; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( (Stereo_Prev = pINChI_Prev->Stereo) && Stereo_Prev->nNumberOfStereoCenters > 0 ) {
                    /* non-empty item */
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                    tot_len += MakeStereoString( Stereo_Prev->nNumber, NULL,
                                                 Stereo_Prev->t_parity,
                                                 0, Stereo_Prev->nNumberOfStereoCenters,
                                                 pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                }
            } else
            if ( pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
            } 
            /* we have found pINChI->Stereo sp3 same as in pINChI_Taut */
            /* output this (current) equivalence as '*', that is, same as tautomeric */
            /* that was printed on the 1st pass. */

            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }

            pINChI_Prev      = NULL; /* pINChI_Prev sp2 does not exist since */
            pINChI_Taut_Prev = NULL; /* pINChI has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;     /* pINChI_Prev sp2 does not exist */
        } else 
        if ( eq2tautPrev ) {
            /* at this point pINChI_Prev does not exist; however, pINChI */
             /*might have been discovered and it is different from pINChI_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Prev      = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0;
        } else {
            /* check whether pINChI and pINChI_Prev have non-zero identical stereo sp3 */
            /*================ compare sp3 to previous =====================*/
            eq2prev =bUseMulipliers &&
                     pINChI && pINChI_Prev &&
                     (Stereo = pINChI->Stereo) && (Stereo_Prev = pINChI_Prev->Stereo) &&
                     Eql_INChI_Stereo( Stereo, EQL_SP3, Stereo_Prev, EQL_SP3, bRelRac );
            if ( eq2prev ) {
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                    if ( (Stereo_Prev = pINChI_Prev->Stereo) && Stereo_Prev->nNumberOfStereoCenters > bRelRac ) {
                        /* pINChI_Prev exists and has sp3 info */
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                        tot_len += MakeStereoString( Stereo_Prev->nNumber, NULL, Stereo_Prev->t_parity,
                                                     0, Stereo_Prev->nNumberOfStereoCenters,
                                                     pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                    }
                    /* else sp3 info is not present in pINChI_Prev */
                } else
                if ( bSecondNonTautPass && pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                     if ( (Stereo_Taut_Prev = pINChI_Taut_Prev->Stereo) && Stereo_Taut_Prev->nNumberOfStereoCenters > bRelRac ) {
                        /* since pINChI_Prev does not exist, pINChI_Taut_Prev is non-tautomeric */
                        /* and it has non-trivial sp3 info. This info has already been printed in the main section */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                        ; /* pINChI_Taut_Prev sp3 info was output in the main stereo section */
                     } else {
                        ; /* pINChI_Taut_Prev exists and has not sp3 info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Prev = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}
/***************************************************************************/
int str_IsoAtoms(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components, int bAbcNumbers,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI,  *pINChI_Prev,  *pINChI_Taut,  *pINChI_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    pINChI_Taut      = NULL;
    pINChI_Prev      = NULL;
    pINChI_Taut_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero only on the 2nd (non-taut) pass */
    eq2tautPrev = 1; /* pINChI_Prev (previous pINChI) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*================ compare isotopic info to previous component =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI[ii2] : NULL;
        }
        /*========= if bSecondNonTautPass then compare iso non-taut to taut non-iso ========*/
        eq2taut = 0;
        if ( !eq2taut && bSecondNonTautPass && bOmitRepetitions ) {
            eq2taut = Eql_INChI_Isotopic( pINChI, pINChI_Taut );
            eq2taut = eq2taut? (iiNUMB | iitNONTAUT) : 0;
        }
        if ( eq2taut ) {
            /* we may be here only in case of the second (non-taut) pass */
            /* current non-taut isotopic info has been found to be same as current tautomeric */
            if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                /* previous component exists; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Prev && (pINChI_Prev->nNumberOfIsotopicAtoms   > 0 ||
                                    pINChI_Prev->nNumberOfIsotopicTGroups > 0) ) {
                    /* non-empty item */
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                    /*  Isotopic atoms */
                    if ( pINChI_Prev->nNumberOfIsotopicAtoms > 0 && nStrLen-tot_len > 2 && !*bOverflow ) { /* dereferenced bOverflow 2004-06-07 */
                        tot_len += MakeIsoAtomString( pINChI_Prev->IsotopicAtom, pINChI_Prev->nNumberOfIsotopicAtoms,
                                                     pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                    }
                    /*  Isotopic tautomeric groups */
                    if ( pINChI_Prev->nNumberOfIsotopicTGroups > 0 && nStrLen-tot_len > 3 && !*bOverflow ) {
                        tot_len += MakeDelim( bAbcNumbers? ITEM_DELIMETER : "(", pStr + tot_len, nStrLen-tot_len, bOverflow);
                        tot_len += MakeIsoTautString( pINChI_Prev->IsotopicTGroup, pINChI_Prev->nNumberOfIsotopicTGroups,
                                                     pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                        if (  !bAbcNumbers ) {
                            tot_len += MakeDelim( ")", pStr + tot_len, nStrLen-tot_len, bOverflow);
                        }
                    }
                }
            } else
            if ( pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
            }
            /* we have found pINChI isotopic info to be same as in pINChI_Taut */
            /* output this (current) equivalence as '*', that is, same as tautomeric */
            /* that was printed on the 1st pass. */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
            pINChI_Prev      = NULL; /* pINChI_Prev isotopic info does not exist since */
            pINChI_Taut_Prev = NULL; /* pINChI has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;     /* pINChI_Prev isotopic info does not exist */
        } else 
        if ( eq2tautPrev ) {
            /* at this point pINChI_Prev does not exist; however, pINChI */
            /* might have been discovered and it is different from pINChI_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Prev      = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0;
        } else {
            /*================ compare iso composition to previous =====================*/
            /* check whether pINChI and pINChI_Prev have non-zero identical isotopic info */
            eq2prev =bUseMulipliers && Eql_INChI_Isotopic( pINChI, pINChI_Prev );
            if ( eq2prev ) {
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                /* pINChI isotopic info is either different or empty. Output pINChI_Prev anyway */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                    if ( (pINChI_Prev->nNumberOfIsotopicAtoms   > 0 ||
                          pINChI_Prev->nNumberOfIsotopicTGroups > 0) ) {
                        /* pINChI_Prev exists and has isotopic info */
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                        /*  Isotopic atoms */
                        if ( pINChI_Prev->nNumberOfIsotopicAtoms > 0 && nStrLen-tot_len > 2 && !*bOverflow ) {
                            tot_len += MakeIsoAtomString( pINChI_Prev->IsotopicAtom, pINChI_Prev->nNumberOfIsotopicAtoms,
                                                         pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                        }
                        /*  Isotopic tautomeric groups */
                        if ( pINChI_Prev->nNumberOfIsotopicTGroups > 0 && nStrLen-tot_len > 3 && !*bOverflow ) {
                            tot_len += MakeDelim( bAbcNumbers? ITEM_DELIMETER : "(", pStr + tot_len, nStrLen-tot_len, bOverflow);
                            tot_len += MakeIsoTautString( pINChI_Prev->IsotopicTGroup, pINChI_Prev->nNumberOfIsotopicTGroups,
                                                         pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                            if (  !bAbcNumbers ) {
                                tot_len += MakeDelim( ")", pStr + tot_len, nStrLen-tot_len, bOverflow);
                            }
                        }
                    }
                    /* else isotopic info is not present in pINChI_Prev */
                }  else
                if ( bSecondNonTautPass && pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                    if ( (pINChI_Taut_Prev->nNumberOfIsotopicAtoms   > 0 ||
                          pINChI_Taut_Prev->nNumberOfIsotopicTGroups > 0) ) {
                        /* since pINChI_Prev does not exist, pINChI_Taut_Prev is non-tautomeric */
                        /* and it has non-trivial isotopic info */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                        ;/* pINChI_Taut_Prev isotopic info was output in the main isotopic section */
                     } else {
                        ; /* pINChI_Taut_Prev exists and has not isotopic info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            /* Fix17: moved here 2004-10-08 */
            pINChI_Prev = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0; /* we do not know whether the item is empty */
        }
        /* Fix17: moved from here 2004-10-08
        pINChI_Prev = pINChI;
        pINChI_Taut_Prev = pINChI_Taut;
        mult = 0;
        */
    }
    return tot_len;
}
/***************************************************************************/
int str_IsoSp2(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI,  *pINChI_Prev,  *pINChI_Taut,  *pINChI_Taut_Prev;
    INChI_Stereo *Stereo, *Stereo_Prev, *Stereo_Taut, *Stereo_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    pINChI_Taut      = NULL;
    pINChI_Prev      = NULL;
    pINChI_Taut_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero if another layer of the current component = current layer */
    eq2tautPrev = 1; /* pINChI_Prev (previous pINChI) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*================ compare sp2 to previous =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI[ii2] : NULL;
        }
        eq2taut = 0;
        /*========= if bSecondNonTautPass then compare iso non-taut stereo to other stereo ========*/
        if ( bSecondNonTautPass && bOmitRepetitions ) {
            /* compare non-tautomeric isotopic to:
             *   a) non-tautomeric non-isotopic
             *   b) tautomeric non-isotopic
             *   c) tautomeric isotopic
             */
            /* a) compare non-tautomeric isotopic to non-tautomeric non-isotopic */
            if ( !eq2taut ) {
                eq2taut = pINChI &&
                                    /* non-taut isotopic */                  /* non-taut non-isotopic */
                          (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI->Stereo) &&
                          Eql_INChI_Stereo( Stereo, EQL_SP2, Stereo_Taut, EQL_SP2, 0 );
                                 /* stereo     isotopic non-taut =  non-taut (stereo) */
                eq2taut = eq2taut? (iiSTEREO | iitISO | iitNONTAUT | iiEq2NONTAUT ) : 0;
            }
            /* b) compare non-tautomeric isotopic to tautomeric non-isotopic */
            if ( !eq2taut ) {
                eq2taut = pINChI && pINChI_Taut &&
                                    /* non-taut isotopic */                  /* taut non-isotopic */
                          (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI_Taut->Stereo) &&
                          Eql_INChI_Stereo( Stereo, EQL_SP2, Stereo_Taut, EQL_SP2, 0 );
                                 /* stereo     isotopic non-taut =  taut (stereo) */
                eq2taut = eq2taut? (iiSTEREO | iitISO | iitNONTAUT ) : 0;
            }
            /* c) compare non-tautomeric isotopic to tautomeric isotopic */
            if ( !eq2taut && bSecondNonTautPass && bOmitRepetitions ) {
                eq2taut = pINChI && pINChI_Taut &&
                          (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI_Taut->StereoIsotopic) &&
                          Eql_INChI_Stereo( Stereo, EQL_SP2, Stereo_Taut, EQL_SP2, 0 );
                                 /* stereo     isotopic non-taut =  isotopic taut (stereo) */
                eq2taut = eq2taut? (iiSTEREO | iitISO | iitNONTAUT | iiEq2ISO) : 0;
            }
#if ( FIX_EMPTY_LAYER_BUG == 1 )
            if ( !eq2taut && pINChI && !((Stereo = pINChI->StereoIsotopic) &&
                Eql_INChI_Stereo( Stereo, EQL_SP2, NULL, EQL_EXISTS, 0 )) ) {
                 /* component has no stereo; check whether it has stereo in the preceding layers */
                if ( pINChI_Taut && (Stereo_Taut = pINChI_Taut->Stereo) && /* F is not empty */
                     Eql_INChI_Stereo( Stereo_Taut, EQL_SP2, NULL, EQL_EXISTS, 0 ) ||
                    !(pINChI_Taut && (Stereo_Taut = pINChI_Taut->Stereo) &&  /* M is empty and ... */
                       Eql_INChI_Stereo( Stereo_Taut, EQL_SP2, NULL, EQL_EXISTS, 0 )) &&
                     (pINChI_Taut && (Stereo_Taut = pINChI_Taut->StereoIsotopic) &&  /* ... MI is not empty */
                       Eql_INChI_Stereo( Stereo_Taut, EQL_SP2, NULL, EQL_EXISTS, 0 )) ) {

                    eq2taut = iiEmpty; /* the component has stereo in the preceding layer  */
                }
            }
#endif
        } else
        /*========= if not bSecondNonTautPass then compare iso taut stereo to non-iso taut ========*/
        if ( !bSecondNonTautPass && bOmitRepetitions ) {
            /* compare tautomeric isotopic to tautomeric non-isotopic */
            if ( !eq2taut ) {
                eq2taut = pINChI &&
                                    /* taut isotopic */                  /* taut non-isotopic */
                          (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI->Stereo) &&
                          Eql_INChI_Stereo( Stereo, EQL_SP2, Stereo_Taut, EQL_SP2, 0 );
                                 /* stereo     isotopic taut =  taut (stereo) */
                eq2taut = eq2taut? (iiSTEREO | iitISO ) : 0;
#if ( FIX_EMPTY_LAYER_BUG == 1 )
                if ( !eq2taut && pINChI && !((Stereo = pINChI->StereoIsotopic) &&
                     Eql_INChI_Stereo( Stereo, EQL_SP2, NULL, EQL_EXISTS, 0 ) ) ) {
                    /* component has no MI stereo; check whether it has stereo in the preceding layer M */
                    if ( (Stereo_Taut = pINChI->Stereo) &&
                         Eql_INChI_Stereo( Stereo_Taut, EQL_SP2, NULL, EQL_EXISTS, 0 ) ) {
                        eq2taut = iiEmpty; /* the component has stereo in the preceding layer  */
                    }
                }
#endif
            }
        }
        if ( eq2taut ) {
            /* we may be here only in case of the current layer found equal in another layer the same component */
            if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                /* previous component exists; output it before output the current component */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( (Stereo_Prev = pINChI_Prev->StereoIsotopic) && Stereo_Prev->nNumberOfStereoBonds > 0 ) {
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                    tot_len += MakeStereoString( Stereo_Prev->nBondAtom1, Stereo_Prev->nBondAtom2,
                                                 Stereo_Prev->b_parity,
                                                 0, Stereo_Prev->nNumberOfStereoBonds,
                                                 pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                }
            } else
            if ( pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                /* do not output stereo of non-tautomeric in non-taut layer: it has been output in the main layer */
            }
            /* we have found another (previously printed) layer of the current component equal to this layer */
            /* output this (current) equivalence mark = EquString(eq2taut) */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
            pINChI_Prev      = NULL; /* pINChI_Prev sp2 does not exist since */
            pINChI_Taut_Prev = NULL; /* pINChI has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;     /* pINChI_Prev and pINChI_Taut_Prev have already been output */
        } else 
        if ( eq2tautPrev ) {
            /* at this point pINChI_Prev does not exist; however, pINChI */
             /*might have been discovered and it is different from pINChI_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Prev      = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0;
        } else {
            /* current layer is different from previously printed layers of the current component */
            /* compare the current layer to this layer of the previous component: */
            /* check whether pINChI and pINChI_Prev have non-zero identical stereo sp2 */
            /*================ compare iso sp2 to previous =====================*/
            eq2prev =bUseMulipliers &&
                     pINChI && pINChI_Prev &&
                     (Stereo = pINChI->StereoIsotopic) && (Stereo_Prev = pINChI_Prev->StereoIsotopic) &&
                     Eql_INChI_Stereo( Stereo, EQL_SP2, Stereo_Prev, EQL_SP2, 0 );
            if ( eq2prev ) {
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                /* the current layer is different from this layer of the previous component */
                /* therefore print the current layer */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                    if ( (Stereo_Prev = pINChI_Prev->StereoIsotopic) && Stereo_Prev->nNumberOfStereoBonds > 0 ) {
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                        tot_len += MakeStereoString( Stereo_Prev->nBondAtom1, Stereo_Prev->nBondAtom2,
                                                     Stereo_Prev->b_parity,
                                                     0, Stereo_Prev->nNumberOfStereoBonds,
                                                     pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                    }
                    /* else sp2 info is not present in pINChI_Prev */
                } else
                /* do not print pINChI_Prev because it either do not exist of have already been printed */
                if ( bSecondNonTautPass && pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                     if ( (Stereo_Taut_Prev = pINChI_Taut_Prev->StereoIsotopic) && Stereo_Taut_Prev->nNumberOfStereoBonds > 0 ) {
                        /* since pINChI_Prev does not exist, pINChI_Taut_Prev is non-tautomeric */
                        /* and it has non-trivial sp2 info */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                        ;/* pINChI_Taut_Prev sp3 info was output in the main stereo section */
                     } else {
                        ; /* pINChI_Taut_Prev exists and has not sp2 info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Prev = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}
/******************************************************************************************/
int str_IsoSp3(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components, int bRelRac,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI,  *pINChI_Prev,  *pINChI_Taut,  *pINChI_Taut_Prev;
    INChI_Stereo *Stereo, *Stereo_Prev, *Stereo_Taut, *Stereo_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    pINChI_Taut      = NULL;
    pINChI_Prev      = NULL;
    pINChI_Taut_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero if another layer of the current component = current layer */
    eq2tautPrev = 1; /* pINChI_Prev (previous pINChI) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
#if( REL_RAC_STEREO_IGN_1_SC == 1 )
#else
    bRelRac = 0;
#endif
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*================ compare sp2 to previous =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI[ii2] : NULL;
        }
        eq2taut = 0;
        /*========= if bSecondNonTautPass then compare iso non-taut stereo to other stereo ========*/
        if ( bSecondNonTautPass && bOmitRepetitions ) {
            /* compare non-tautomeric isotopic to:
             *   a) non-tautomeric non-isotopic
             *   b) tautomeric non-isotopic
             *   c) tautomeric isotopic
             */
            /* a) compare non-tautomeric isotopic to non-tautomeric non-isotopic */
            if ( !eq2taut ) {
                eq2taut = pINChI && /* non-taut isotopic */                  /* non-taut non-isotopic */
                          (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI->Stereo) &&
                          Eql_INChI_Stereo( Stereo, EQL_SP3, Stereo_Taut, EQL_SP3, bRelRac );
                                 /* stereo     isotopic non-taut =  non-taut (stereo) */
                eq2taut = eq2taut? (iiSTEREO | iitISO | iitNONTAUT | iiEq2NONTAUT ) : 0;
            }
            /* b) compare non-tautomeric isotopic to tautomeric non-isotopic */
            if ( !eq2taut ) {
                eq2taut = pINChI && pINChI_Taut &&
                                    /* non-taut isotopic */                  /* taut non-isotopic */
                          (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI_Taut->Stereo) &&
                          Eql_INChI_Stereo( Stereo, EQL_SP3, Stereo_Taut, EQL_SP3, bRelRac );
                                 /* stereo     isotopic non-taut =  taut (stereo) */
                eq2taut = eq2taut? (iiSTEREO | iitISO | iitNONTAUT ) : 0;
            }
            /* c) compare non-tautomeric isotopic to tautomeric isotopic */
            if ( !eq2taut && bSecondNonTautPass && bOmitRepetitions ) {
                eq2taut = pINChI && pINChI_Taut &&
                          (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI_Taut->StereoIsotopic) &&
                          Eql_INChI_Stereo( Stereo, EQL_SP3, Stereo_Taut, EQL_SP3, bRelRac );
                                 /* stereo     isotopic non-taut =  isotopic taut (stereo) */
                eq2taut = eq2taut? (iiSTEREO | iitISO | iitNONTAUT | iiEq2ISO) : 0;
            }
#if ( FIX_EMPTY_LAYER_BUG == 1 )
            if ( !eq2taut && pINChI && !((Stereo = pINChI->StereoIsotopic) &&
                Eql_INChI_Stereo( Stereo, EQL_SP3, NULL, EQL_EXISTS, 0 )) ) {
                 /* component has no stereo; check whether it has stereo in the preceding layers */
                if ( pINChI_Taut && (Stereo_Taut = pINChI_Taut->Stereo) && /* F is not empty */
                     Eql_INChI_Stereo( Stereo_Taut, EQL_SP3, NULL, EQL_EXISTS, 0 ) ||
                    !(pINChI_Taut && (Stereo_Taut = pINChI_Taut->Stereo) &&  /* M is empty and ... */
                       Eql_INChI_Stereo( Stereo_Taut, EQL_SP3, NULL, EQL_EXISTS, 0 )) &&
                     (pINChI_Taut && (Stereo_Taut = pINChI_Taut->StereoIsotopic) &&  /* ... MI is not empty */
                       Eql_INChI_Stereo( Stereo_Taut, EQL_SP3, NULL, EQL_EXISTS, 0 )) ) {

                    eq2taut = iiEmpty; /* the component has stereo in the preceding layer  */
                }
            }
#endif
        } else
        /*========= if not bSecondNonTautPass then compare iso taut stereo to non-iso taut ========*/
        if ( !bSecondNonTautPass && bOmitRepetitions ) {
            /* compare tautomeric isotopic to tautomeric non-isotopic */
            if ( !eq2taut ) {
                eq2taut = pINChI &&
                                    /* taut isotopic */                  /* taut non-isotopic */
                          (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI->Stereo) &&
                          Eql_INChI_Stereo( Stereo, EQL_SP3, Stereo_Taut, EQL_SP3, bRelRac );
                                 /* stereo     isotopic taut =  taut (stereo) */
                eq2taut = eq2taut? (iiSTEREO | iitISO ) : 0;
#if ( FIX_EMPTY_LAYER_BUG == 1 )
                if ( !eq2taut && pINChI && !((Stereo = pINChI->StereoIsotopic) &&
                     Eql_INChI_Stereo( Stereo, EQL_SP3, NULL, EQL_EXISTS, 0 ) ) ) {
                    /* component has no MI stereo; check whether it has stereo in the preceding layer M */
                    if ( (Stereo_Taut = pINChI->Stereo) &&
                         Eql_INChI_Stereo( Stereo_Taut, EQL_SP3, NULL, EQL_EXISTS, 0 ) ) {
                        eq2taut = iiEmpty; /* the component has stereo in the preceding layer  */
                    }
                }
#endif
            }
        }
        if ( eq2taut ) {
            /* we may be here only in case of the current layer found equal in another layer the same component */
            if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                /* previous component exists; output it before output the current component */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( (Stereo_Prev = pINChI_Prev->StereoIsotopic) && Stereo_Prev->nNumberOfStereoCenters > bRelRac ) {
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                    tot_len += MakeStereoString( Stereo_Prev->nNumber, NULL, Stereo_Prev->t_parity,
                                                 0, Stereo_Prev->nNumberOfStereoCenters,
                                                 pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                }
            } else
            if ( pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                /* do not output stereo of non-tautomeric in non-taut layer: it has been output in the main layer */
            }
            /* we have found another (previously printed) layer of the current component equal to this layer */
            /* output this (current) equivalence mark = EquString(eq2taut) */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
            pINChI_Prev      = NULL; /* pINChI_Prev sp2 does not exist since */
            pINChI_Taut_Prev = NULL; /* pINChI has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;     /* pINChI_Prev and pINChI_Taut_Prev have already been output */
        } else 
        if ( eq2tautPrev ) {
            /* at this point pINChI_Prev does not exist; however, pINChI */
             /*might have been discovered and it is different from pINChI_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Prev      = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0;
        } else {
            /* current layer is different from previously printed layers of the current component */
            /* compare the current layer to this layer of the previous component: */
            /* check whether pINChI and pINChI_Prev have non-zero identical stereo sp2 */
            /*================ compare iso sp3 to previous =====================*/
            eq2prev =bUseMulipliers && pINChI && pINChI_Prev &&
                     (Stereo = pINChI->StereoIsotopic) && (Stereo_Prev = pINChI_Prev->StereoIsotopic) &&
                     Eql_INChI_Stereo( Stereo, EQL_SP3, Stereo_Prev, EQL_SP3, bRelRac );
            if ( eq2prev ) {
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                    if ( (Stereo_Prev = pINChI_Prev->StereoIsotopic) && Stereo_Prev->nNumberOfStereoCenters > bRelRac ) {
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                        tot_len += MakeStereoString( Stereo_Prev->nNumber, NULL, Stereo_Prev->t_parity,
                                                     0, Stereo_Prev->nNumberOfStereoCenters,
                                                     pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                    }
                    /* else sp3 info is not present in pINChI_Prev */
                } else
                /* do not print pINChI_Prev because it either do not exist of have already been printed */
                if ( bSecondNonTautPass && pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                     if ( (Stereo_Taut_Prev = pINChI_Taut_Prev->StereoIsotopic) && Stereo_Taut_Prev->nNumberOfStereoCenters > bRelRac ) {
                        /* since pINChI_Prev does not exist, pINChI_Taut_Prev is non-tautomeric */
                        /* and it has non-trivial sp2 info */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                        ;/* pINChI_Taut_Prev sp3 info was output in the main stereo section */
                     } else {
                        ; /* pINChI_Taut_Prev exists and has not sp3 info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Prev = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}
/***************************************************************************/
int str_AuxEqu(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI_Aux    *pINChI_Aux = NULL, *pINChI_Aux_Prev, *pINChI_Aux_Taut, *pINChI_Aux_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    pINChI_Aux_Prev      = NULL;
    pINChI_Aux_Taut      = NULL;
    pINChI_Aux_Taut_Prev = NULL;

    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero only on the 2nd (non-taut) pass */
    eq2tautPrev = 1; /* pINChI_Aux_Prev (previous pINChI_Aux) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI_Aux = (i < num_components && (is = is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI_Aux[ii] : NULL;
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Aux_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI_Aux[ii2] : NULL;
        }
        /*================ compare non-iso non-taut equivalence info to non-iso taut ========*/
        eq2taut = bSecondNonTautPass && bOmitRepetitions &&
                  Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU, pINChI_Aux_Taut, EQL_EQU );
        eq2taut = eq2taut? (iiEQU | iitNONTAUT) : 0;
        if ( eq2taut ) {
            /* we may be here only in case of the second (non-taut) pass */
            /* current non-taut equivalence has been found to be same as tautomeric */
            if ( pINChI_Aux_Prev && pINChI_Aux_Prev->nNumberOfAtoms ) {
                /* previous component exists */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( bHasEquString( pINChI_Aux_Prev->nConstitEquNumbers, pINChI_Aux_Prev->nNumberOfAtoms) ) {
                    /* output previous component(s) equivalence since it was found to be non-trivial */
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                    tot_len += MakeEquString( pINChI_Aux_Prev->nConstitEquNumbers, pINChI_Aux_Prev->nNumberOfAtoms, 0,
                                             pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                } else {
                    ; /* pINChI_Aux_Prev exists and has only trivial equivalence info */
                }
            } else
            if ( pINChI_Aux_Taut_Prev && pINChI_Aux_Taut_Prev->nNumberOfAtoms ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
            }
            /* we have found pINChI_Aux->nConstitEquNumbers same as in pINChI_Aux_Taut */
            /* output this (current) equivalence as '*', that is, same as tautomeric */
            /* that was printed on the 1st pass. */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
            pINChI_Aux_Prev      = NULL; /* pINChI_Aux_Prev does not exist since */
            pINChI_Aux_Taut_Prev = NULL; /* pINChI_Aux has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;
        } else
        if ( eq2tautPrev ) {
            /* at this point pINChI_Aux_Prev does not exist; however, pINChI_Aux */
             /*might have been discovered and it is different from pINChI_Aux_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Aux_Prev      = pINChI_Aux;
            pINChI_Aux_Taut_Prev = pINChI_Aux_Taut;
            mult = 0;
        } else {
            /* check whether pINChI_Aux and pINChI_Aux_Prev have identical non-trivial equivalence info */
            eq2prev = bUseMulipliers &&
                      Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU, pINChI_Aux_Prev, EQL_EQU );
            if ( eq2prev ) {
                /* eq. info is same and non-trivial */
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                /* pINChI_Aux eq. info is either different or trivial. Output pINChI_Aux_Prev anyway */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Aux_Prev && pINChI_Aux_Prev->nNumberOfAtoms ) {
                     if ( bHasEquString( pINChI_Aux_Prev->nConstitEquNumbers, pINChI_Aux_Prev->nNumberOfAtoms) ) {
                        /* pINChI_Aux_Prev exists and has equivalence info */
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                        tot_len += MakeEquString( pINChI_Aux_Prev->nConstitEquNumbers, pINChI_Aux_Prev->nNumberOfAtoms, 0,
                                                 pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                     } else {
                        ; /* pINChI_Aux_Prev exists and has only trivial equivalence info */
                     }
                } else
                if ( bSecondNonTautPass && pINChI_Aux_Taut_Prev && pINChI_Aux_Taut_Prev->nNumberOfAtoms ) {
                     if ( bHasEquString( pINChI_Aux_Taut_Prev->nConstitEquNumbers, pINChI_Aux_Taut_Prev->nNumberOfAtoms) ) {
                        /* since pINChI_Aux_Prev does not exist, pINChI_Aux_Taut_Prev is non-tautomeric */
                        /* and it has non-trivial equivalence info. This info has already been printed in the main section  */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                     } else {
                         ; /* pINChI_Aux_Taut_Prev exists and has only trivial equivalence info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Aux_Prev      = pINChI_Aux;
            pINChI_Aux_Taut_Prev = pINChI_Aux_Taut;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}
/******************************************************************************************/
int str_AuxInvSp3(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI,  *pINChI_Prev,  *pINChI_Taut,  *pINChI_Taut_Prev;
    INChI_Stereo *Stereo, *Stereo_Prev, *Stereo_Taut, *Stereo_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    /***************
      inverted sp3
    ****************/
    pINChI_Taut      = NULL;
    pINChI_Prev      = NULL;
    pINChI_Taut_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero if another layer of the current component = current layer */
    eq2tautPrev = 1; /* pINChI_Prev (previous pINChI) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*================ compare sp2 to previous =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI[ii2] : NULL;
        }
        eq2taut = 0;
        /*========= if bSecondNonTautPass then compare iso non-taut stereo to other stereo ========*/
        if ( bSecondNonTautPass && bOmitRepetitions ) {
            /* compare non-tautomeric inverted to:
             *   a) tautomeric inverted
             *   b) Inverted(tautomeric)
             *   c) Inverted(non-tautomeric)
             */
            /* a) compare non-tautomeric inverted to tautomeric inverted */
            if ( !eq2taut ) {
                eq2taut = pINChI && pINChI_Taut &&
                          /* non-taut inverted */          /* taut invertedc */
                  (Stereo = pINChI->Stereo) && (Stereo_Taut = pINChI_Taut->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3_INV, 0 );
                                 /* stereo-inv      non-taut =  taut (stereo-inv) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitNONTAUT ) : 0;
            }
            /* b) compare non-tautomeric inverted to Inverted(tautomeric stereo) */
            if ( !eq2taut ) {
                eq2taut = pINChI && pINChI_Taut &&
                  (Stereo = pINChI->Stereo) && (Stereo_Taut = pINChI_Taut->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3, 0 );
                                 /* stereo-inv    non-taut =  Inv(taut stereo) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitNONTAUT | iiEq2INV) : 0;
            }
            /* c) compare non-tautomeric inverted to Inverted(non-tautomeric stereo) */
            if ( !eq2taut ) {
                eq2taut = pINChI &&
                  (Stereo = pINChI->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo, EQL_SP3, 0 );
                                 /* stereo-inv    non-taut =  Inv(non-taut stereo) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitNONTAUT | iiEq2INV | iiEq2NONTAUT) : 0;
            }
#if ( FIX_EMPTY_LAYER_BUG == 1 )
            if ( !eq2taut && pINChI && pINChI_Taut &&
                 !((Stereo = pINChI->Stereo) && Eql_INChI_Stereo( Stereo, EQL_SP3_INV, NULL, EQL_EXISTS, 0 ))) {
                if ( (Stereo_Taut = pINChI_Taut->Stereo) &&
                     Eql_INChI_Stereo( Stereo_Taut, EQL_SP3, NULL, EQL_EXISTS, 0 ) ) {

                    eq2taut = iiEmpty; /* the current is empty while the preceding (taut) is not */
                }
            }
#endif
        } else
        /*========= if not bSecondNonTautPass then compare inv taut stereo to various taut stereo ========*/
        if ( !bSecondNonTautPass && bOmitRepetitions ) {
            /* compare tautomeric inverted to Invetred(tautomeric) */
            if ( !eq2taut ) {
                eq2taut = pINChI &&
                  (Stereo = pINChI->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo, EQL_SP3, 0 );
                                 /* stereo     isotopic taut =  taut (stereo) */
                eq2taut = eq2taut? (iiSTEREO_INV | iiEq2INV ) : 0;
            }
        }
        if ( eq2taut ) {
            /* we may be here only in case of the current layer found equal in another layer the same component */
            if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                /* previous component exists; output it before output the current component */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( (Stereo_Prev = pINChI_Prev->Stereo) && Stereo_Prev->nNumberOfStereoCenters > 0 ) {
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                    tot_len += MakeStereoString( Stereo_Prev->nNumber, NULL, Stereo_Prev->t_parityInv,
                                                 0, Stereo_Prev->nNumberOfStereoCenters,
                                                 pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                }
            } else
            if ( pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                /* do not output stereo of non-tautomeric in non-taut layer: it has been output in the main layer */
            }
            /* we have found another (previously printed) layer of the current component equal to this layer */
            /* output this (current) equivalence mark = EquString(eq2taut) */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
            pINChI_Prev      = NULL; /* pINChI_Prev sp2 does not exist since */
            pINChI_Taut_Prev = NULL; /* pINChI has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;     /* pINChI_Prev and pINChI_Taut_Prev have already been output */
        } else 
        if ( eq2tautPrev ) {
            /* at this point pINChI_Prev does not exist; however, pINChI */
             /*might have been discovered and it is different from pINChI_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Prev      = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0;
        } else {
            /* current layer is different from previously printed layers of the current component */
            /* compare the current layer to this layer of the previous component: */
            /* check whether pINChI and pINChI_Prev have non-zero identical stereo sp2 */
            /*================ compare iso sp3 to previous =====================*/
            eq2prev =bUseMulipliers &&
                     pINChI && pINChI_Prev &&
                     /* do both have stereo? */
                     (Stereo = pINChI->Stereo) && (Stereo_Prev = pINChI_Prev->Stereo) &&
                     /* is their inverted stereo same? */
                     Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Prev, EQL_SP3_INV, 0 );
            if ( eq2prev ) {
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                    if ( (Stereo_Prev = pINChI_Prev->Stereo) &&
                          Stereo_Prev->nNumberOfStereoCenters > 0 && Stereo_Prev->nCompInv2Abs ) {
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                        tot_len += MakeStereoString( Stereo_Prev->nNumberInv, NULL, Stereo_Prev->t_parityInv,
                                                     0, Stereo_Prev->nNumberOfStereoCenters,
                                                     pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                    }
                    /* else sp3 info is not present in pINChI_Prev */
                } else
                /* do not print pINChI_Prev because it either do not exist of have already been printed */
                if ( bSecondNonTautPass && pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                     if ( (Stereo_Taut_Prev = pINChI_Taut_Prev->Stereo) &&
                           Stereo_Taut_Prev->nNumberOfStereoCenters > 0 && Stereo_Taut_Prev->nCompInv2Abs ) {
                        /* since pINChI_Prev does not exist, pINChI_Taut_Prev is non-tautomeric */
                        /* and it has non-trivial inv sp3 info. It has already been printed in the main section */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                        ;/* pINChI_Taut_Prev sp3 info was output in the main stereo section */
                     } else {
                        ; /* pINChI_Taut_Prev exists and has not sp3 info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Prev = pINChI;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}
/***************************************************************************/
int str_AuxInvSp3Numb(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is0 /*, *is2*/;
    INChI        *pINChI,  *pINChI_Taut;
    INChI_Aux    *pINChI_Aux, *pINChI_Aux_Prev, *pINChI_Aux_Taut;
    INChI_Stereo *Stereo, *Stereo_Taut;
    int          eq2taut, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    /**************************************************
     * specificity of numbering: there is no previous *
     * component because no repetition is possible    *
     **************************************************/
    pINChI          = NULL;
    pINChI_Taut     = NULL;
    pINChI_Aux      = NULL;
    pINChI_Aux_Taut = NULL;
    pINChI_Aux_Prev = NULL;
    bNext       = 0;
    is          = NULL;
    is0         = pINChISort;
    /*is2         = bSecondNonTautPass? pINChISort2 : NULL;*/
    eq2taut     = 0; /* may be non-zero if another layer of the current component = current layer */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i < num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        is=is0+i;
        pINChI = (0 <= (ii=GET_II(bOutType,is)))? is->pINChI[ii] : NULL;
        pINChI_Aux = pINChI? is->pINChI_Aux[ii] : NULL;
        /*================ to compare to previously printed =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was printed on the 1st pass */
            pINChI_Taut     = (0 <= (ii2=GET_II(OUT_T1,is)))? is->pINChI[ii2] : NULL;
            pINChI_Aux_Taut = pINChI_Taut? is->pINChI_Aux[ii2] : NULL;
        }

        eq2taut = 0;
        /*========= if bSecondNonTautPass then compare inv non-taut stereo to other stereo ========*/
        if ( bSecondNonTautPass && bOmitRepetitions &&
             pINChI && (Stereo = pINChI->Stereo) && Stereo->nCompInv2Abs ) {
            /* compare non-tautomeric inverted stereo numbering to:
             *   a) tautomeric numbering
             *   b) non-tautomeric numbering
             *   c) tautomeric inverted stereo numbering
             */
            /* a) compare non-tautomeric inverted stereo numbering to tautomeric numbering */
            if ( !eq2taut ) {
                eq2taut = pINChI_Taut &&
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV, pINChI_Aux_Taut, EQL_NUM );
                                 /* stereo-inv     numbering  non-taut =  taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iiNUMB | iitNONTAUT ) : 0;
            }
            /* b) compare non-tautomeric inverted stereo numbering to non-tautomeric numbering */
            if ( !eq2taut ) {
                eq2taut =
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV, pINChI_Aux, EQL_NUM );
                                 /* stereo-inv     numb.     non-taut =  non-taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iiNUMB | iitNONTAUT | iiEq2NONTAUT ) : 0;
            }
            /* c) compare non-tautomeric inverted stereo numbering to tautomeric inverted stereo numbering */
            if ( !eq2taut ) {
                eq2taut = pINChI_Taut &&
                  (Stereo_Taut = pINChI_Taut->Stereo) && Stereo_Taut->nCompInv2Abs &&
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV, pINChI_Aux_Taut, EQL_NUM_INV );
                                 /* stereo-inv     numb.     non-taut =  taut inv stereo numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iiNUMB | iitNONTAUT | iiEq2INV ) : 0;
            }
        } else
        /*========= if not bSecondNonTautPass then compare inv taut stereo numb to taut numb ========*/
        if ( !bSecondNonTautPass && bOmitRepetitions &&
             pINChI &&  (Stereo = pINChI->Stereo) && Stereo->nCompInv2Abs ) {
            /* compare tautomeric inverted stereo numbering to tautomeric numbering */
            if ( !eq2taut ) {
                eq2taut = 
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV, pINChI_Aux, EQL_NUM );
                                 /* stereo-inv     numbering  (taut) =  taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iiNUMB ) : 0;
            }
        }
        if ( eq2taut ) {
            /* we have found another (previously printed) layer of the current component equal to this layer */
            /* output this (current) equivalence mark = EquString(eq2taut) */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
        } else {
            /* current layer is different from previously printed layers of the current component */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            if ( bNext ++ ) {
                tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI && pINChI_Aux && pINChI_Aux->nNumberOfAtoms &&
                 (Stereo = pINChI->Stereo) && Stereo->nNumberOfStereoCenters &&
                 Stereo->nCompInv2Abs && pINChI_Aux->nOrigAtNosInCanonOrdInv ) {
                    tot_len += MakeCtString( pINChI_Aux->nOrigAtNosInCanonOrdInv,
                                             pINChI_Aux->nNumberOfAtoms, 0, NULL, 0,
                                             pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
            }
            /* else inv stereo info is not present in pINChI */
        }
    }
    if ( multPrevEquStr && pPrevEquStr ) {
        /* the new EqStr of the last item has not been printed; output it now */
        if ( bNext ++ ) {
            tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
        }
        tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
        pPrevEquStr = NULL;
        multPrevEquStr = 0;
    }
    return tot_len;
}
/***************************************************************************/
int str_AuxIsoNumb(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is0 /*, *is2*/;
    INChI        *pINChI,  *pINChI_Taut;
    INChI_Aux    *pINChI_Aux, *pINChI_Aux_Prev, *pINChI_Aux_Taut;
    int          eq2taut, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    /**************************************************
     * specificity of numbering: there is no previous *
     * component because no repetition is possible    *
     **************************************************/
    pINChI          = NULL;  /* not used here, for debug only */
    pINChI_Taut     = NULL;  /* not used here, for debug only */
    pINChI_Aux      = NULL;
    pINChI_Aux_Taut = NULL;
    pINChI_Aux_Prev = NULL;
    bNext       = 0;
    is          = NULL;
    is0         = pINChISort;
    /*is2         = bSecondNonTautPass? pINChISort2 : NULL;*/
    eq2taut     = 0; /* may be non-zero if another layer of the current component = current layer */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i < num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        is=is0+i;
        pINChI_Aux = (i < num_components && 0 <= (ii=GET_II(bOutType,is)))? is->pINChI_Aux[ii] : NULL;
        /*================ to compare to previously printed =====================*/
        if ( bSecondNonTautPass ) {
            pINChI_Aux_Taut = (0 <= (ii2=GET_II(OUT_T1,is)))? is->pINChI_Aux[ii2] : NULL;
        }
        eq2taut = 0;
        /*========= if bSecondNonTautPass then compare iso non-taut numb to other numb ========*/
        if ( bSecondNonTautPass && bOmitRepetitions && pINChI_Aux && pINChI_Aux->bIsIsotopic ) {
            /* compare non-tautomeric isotopic numbering to:
             *   a) tautomeric numbering
             *   b) non-tautomeric numbering
             *   c) tautomeric isotopic numbering
             */
            /* a) compare non-tautomeric isotopic numbering to tautomeric numbering */
            if ( !eq2taut ) {
                eq2taut = Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_ISO, pINChI_Aux_Taut, EQL_NUM );
                                 /* numbering  non-taut isotopic =  taut numbering */
                eq2taut = eq2taut? ( iiNUMB | iitNONTAUT | iitISO ) : 0;
            }
            /* b) compare non-tautomeric isotopic numbering to non-tautomeric numbering */
            if ( !eq2taut ) {
                eq2taut = Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_ISO, pINChI_Aux, EQL_NUM );
                                 /* numbering  non-taut isotopic =  non-taut numbering */
                eq2taut = eq2taut? ( iiNUMB | iitNONTAUT | iitISO | iiEq2NONTAUT ) : 0;
            }
            /* c) compare non-tautomeric isotopic numbering to tautomeric isotopic numbering */
            if ( !eq2taut ) {
                eq2taut = Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_ISO, pINChI_Aux_Taut, EQL_NUM_ISO );
                                 /* numbering  non-taut isotopic =  taut isotopic numbering */
                eq2taut = eq2taut? ( iiNUMB | iitNONTAUT | iitISO | iiEq2ISO ) : 0;
            }
        } else
        /*========= if not bSecondNonTautPass then compare inv taut stereo numb to taut numb ========*/
        if ( !bSecondNonTautPass && bOmitRepetitions && pINChI_Aux && pINChI_Aux->bIsIsotopic ) {
            /* compare tautomeric isotopic numbering to tautomeric non-isotopic numbering */
            if ( !eq2taut ) {
                eq2taut = Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_ISO, pINChI_Aux, EQL_NUM_ISO );
                                 /* stereo-inv     numbering  (taut) =  taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iiNUMB ) : 0;
            }
        }
        if ( eq2taut ) {
            /* we have found another (previously printed) layer of the current component equal to this layer */
            /* output this (current) equivalence mark = EquString(eq2taut) */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
        } else {
            /* current layer is different from previously printed layers of the current component */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            if ( bNext ++ ) {
                tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI_Aux && pINChI_Aux->nNumberOfAtoms && pINChI_Aux->bIsIsotopic &&
                 pINChI_Aux->nIsotopicOrigAtNosInCanonOrd ) {
                    tot_len += MakeCtString( pINChI_Aux->nIsotopicOrigAtNosInCanonOrd,
                                             pINChI_Aux->nNumberOfAtoms, 0, NULL, 0,
                                             pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
            }
            /* else isotopic numbering is not present in pINChI */
        }
    }
    if ( multPrevEquStr && pPrevEquStr ) {
        /* the new EqStr of the last item has not been printed; output it now */
        if ( bNext ++ ) {
            tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
        }
        tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
        pPrevEquStr = NULL;
        multPrevEquStr = 0;
    }
    return tot_len;
}
/***************************************************************************/
int str_AuxIsoEqu(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI_Aux    *pINChI_Aux, *pINChI_Aux_Prev, *pINChI_Aux_Taut, *pINChI_Aux_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    pINChI_Aux           = NULL;
    pINChI_Aux_Prev      = NULL;
    pINChI_Aux_Taut      = NULL;
    pINChI_Aux_Taut_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero only on the 2nd (non-taut) pass */
    eq2tautPrev = 1; /* pINChI_Aux_Prev (previous pINChI_Aux) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI_Aux = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI_Aux[ii] : NULL;
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Aux_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI_Aux[ii2] : NULL;
        }
        /*================ compare iso non-taut equivalence info to non-iso taut ========*/
        eq2taut = 0;
        if ( bSecondNonTautPass && bOmitRepetitions && pINChI_Aux && pINChI_Aux->bIsIsotopic ) {
            /**************************************************
             * compare isotopic non-tautomeric equivalence to:
             *    a) tautomeric
             *    b) non-tautomeric
             *    c) isotopic tautomeric
             */
            if ( !eq2taut ) {
                /* compare isotopic non-tautomeric equivalence to tautomeric */
                eq2taut = Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU_ISO, pINChI_Aux_Taut, EQL_EQU );
                                   /* equ   non-taut     isotopic = tautomeric*/
                eq2taut = eq2taut? (iiEQU | iitNONTAUT | iitISO) : 0;
            }
            if ( !eq2taut ) {
                /* compare isotopic non-tautomeric equivalence to non-tautomeric */
                eq2taut = Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU_ISO, pINChI_Aux, EQL_EQU );
                                   /* equ  non-taut    isotopic = non-tautomeric*/
                eq2taut = eq2taut? (iiEQU | iitNONTAUT | iitISO | iiEq2NONTAUT) : 0;
            }
            if ( !eq2taut ) {
                /* compare isotopic non-tautomeric equivalence to isotopic tautomeric */
                eq2taut = Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU_ISO, pINChI_Aux_Taut, EQL_EQU_ISO );
                                 /* equ   non-taut     isotopic = isotopic tautomeric*/
                eq2taut = eq2taut? (iiEQU | iitNONTAUT | iitISO | iiEq2ISO) : 0;
            }
        } else
        if ( !bSecondNonTautPass && bOmitRepetitions && pINChI_Aux && pINChI_Aux->bIsIsotopic ) {
            /**************************************************
             * compare isotopic tautomeric equivalence to:
             *    a) non-isotopic tautomeric
             */
            if ( !eq2taut ) {
                /* compare isotopic tautomeric equivalence to tautomeric */
                eq2taut = Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU_ISO, pINChI_Aux, EQL_EQU );
                                   /* equ   taut-isotopic = tautomeric*/
                eq2taut = eq2taut? (iiEQU | iitISO) : 0;
            }
        }
        if ( eq2taut ) {
            /* we may be here only in case of the second (non-taut) pass */
            /* current non-taut equivalence has been found to be same as tautomeric */
            if ( pINChI_Aux_Prev && pINChI_Aux_Prev->nNumberOfAtoms ) {
                /* previous component exists */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( bHasEquString( pINChI_Aux_Prev->nConstitEquIsotopicNumbers, pINChI_Aux_Prev->nNumberOfAtoms) ) {
                    /* output previous component(s) equivalence since it was found to be non-trivial */
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                    tot_len += MakeEquString( pINChI_Aux_Prev->nConstitEquIsotopicNumbers, pINChI_Aux_Prev->nNumberOfAtoms, 0,
                                             pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                } else {
                    ; /* pINChI_Aux_Prev exists and has only trivial equivalence info */
                }
            } else
            if ( pINChI_Aux_Taut_Prev && pINChI_Aux_Taut_Prev->nNumberOfAtoms ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
            }
            /* we have found pINChI_Aux->pINChI_Aux->nConstitEquIsotopicNumbers same as in pINChI_Aux_Taut */
            /* output this (current) equivalence as '*', that is, same as tautomeric */
            /* that was printed on the 1st pass. */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
            pINChI_Aux_Prev      = NULL; /* pINChI_Aux_Prev does not exist since */
            pINChI_Aux_Taut_Prev = NULL; /* pINChI_Aux has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;
        } else
        if ( eq2tautPrev ) {
            /* at this point pINChI_Aux_Prev does not exist; however, pINChI_Aux */
             /*might have been discovered and it is different from pINChI_Aux_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Aux_Prev      = pINChI_Aux;
            pINChI_Aux_Taut_Prev = pINChI_Aux_Taut;
            mult = 0;
        } else {
            /* check whether pINChI_Aux and pINChI_Aux_Prev have identical non-trivial equivalence info */
            eq2prev = bUseMulipliers && Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU_ISO, pINChI_Aux_Prev, EQL_EQU_ISO );
            if ( eq2prev ) {
                /* eq. info is same and non-trivial */
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                /* pINChI_Aux eq. info is either different or trivial. Output pINChI_Aux_Prev anyway */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Aux_Prev && pINChI_Aux_Prev->nNumberOfAtoms ) {
                     if ( bHasEquString( pINChI_Aux_Prev->nConstitEquIsotopicNumbers, pINChI_Aux_Prev->nNumberOfAtoms) ) {
                        /* pINChI_Aux_Prev exists and has equivalence info */
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                        tot_len += MakeEquString( pINChI_Aux_Prev->nConstitEquIsotopicNumbers, pINChI_Aux_Prev->nNumberOfAtoms, 0,
                                                 pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                     } else {
                        ; /* pINChI_Aux_Prev exists and has only trivial equivalence info */
                     }
                } else
                if ( bSecondNonTautPass && pINChI_Aux_Taut_Prev && pINChI_Aux_Taut_Prev->nNumberOfAtoms ) {
                     if ( bHasEquString( pINChI_Aux_Taut_Prev->nConstitEquIsotopicNumbers, pINChI_Aux_Taut_Prev->nNumberOfAtoms) ) {
                        /* since pINChI_Aux_Prev does not exist, pINChI_Aux_Taut_Prev is non-tautomeric */
                        /* and it has non-trivial equivalence info. This info has already been printed in the main section  */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                     } else {
                         ; /* pINChI_Aux_Taut_Prev exists and has only trivial equivalence info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Aux_Prev      = pINChI_Aux;
            pINChI_Aux_Taut_Prev = pINChI_Aux_Taut;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}
/******************************************************************************************/
int str_AuxInvIsoSp3(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI,  *pINChI_Prev,  *pINChI_Taut,  *pINChI_Taut_Prev;
    INChI_Stereo *Stereo, *Stereo_Prev, *Stereo_Taut, *Stereo_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    /********************************
         inverted isotopic sp3
    *********************************/
    pINChI_Taut      = NULL;
    pINChI_Prev      = NULL;
    pINChI_Taut_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero if another layer of the current component = current layer */
    eq2tautPrev = 1; /* pINChI_Prev (previous pINChI) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*================ compare sp2 to previous =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI[ii2] : NULL;
        }
        eq2taut = 0;
        /*========= if bSecondNonTautPass then compare iso non-taut stereo to other stereo ========*/
        if ( bSecondNonTautPass && bOmitRepetitions && pINChI && pINChI->nNumberOfIsotopicAtoms+pINChI->nNumberOfIsotopicTGroups > 0 ) {
            /* compare non-tautomeric isotopic inverted to:
             *   a) tautomeric inverted
             *   b) *non-tautomeric inverted
             *   c) *isotopic tautomeric inverted
             *   d) Inverted(tautomeric)
             *   e) *Inverted(tautomeric isotopic)
             *   f) Inverted(non-tautomeric)
             *   g) *Inverted(non-tautomeric isotopic)
             */
            /* a) compare non-tautomeric isotopic inverted to tautomeric inverted */
            if ( !eq2taut ) {
                eq2taut = pINChI && pINChI_Taut &&
                          /* non-taut inverted */          /* taut invertedc */
                  (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI_Taut->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3_INV, 0 );
                                 /* stereo-inv    isotopic  non-taut =  taut (stereo-inv) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iitNONTAUT ) : 0;
            }
            /* b) compare non-tautomeric isotopic inverted to non-tautomeric inverted */
            if ( !eq2taut ) {
                eq2taut = pINChI &&                    /* it is non-taut non-iso stereo */
                  (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3_INV, 0 );
                                 /* stereo-inv    isotopic non-taut =  non-taut stereo-inv */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iitNONTAUT | iiEq2NONTAUT) : 0;
            }
            /* c) compare non-tautomeric isotopic inverted to isotopic tautomeric inverted */
            if ( !eq2taut ) {
                eq2taut = pINChI && pINChI_Taut &&
                          /* non-taut iso. inverted */             /* taut iso. inverted */
                  (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI_Taut->StereoIsotopic) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3_INV, 0 );
                                 /* stereo-inv    isotopic  non-taut =  taut iso. stereo-inv */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iitNONTAUT | iiEq2ISO ) : 0;
            }
            /* d) compare non-tautomeric inverted to Inverted(tautomeric stereo) */
            if ( !eq2taut ) {
                eq2taut = pINChI && pINChI_Taut &&
                  (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI_Taut->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3_INV, 0 );
                                 /* stereo-inv   isotopic  non-taut =  Inv(non-iso taut stereo) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iitNONTAUT | iiEq2INV) : 0;
            }
            /* e) compare non-tautomeric inverted to Inverted(isotopic tautomeric stereo) */
            if ( !eq2taut ) {
                eq2taut = pINChI && pINChI_Taut &&
                  (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI_Taut->StereoIsotopic) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3, 0 );
                                 /* stereo-inv   isotopic  non-taut =  Inv(iso taut stereo) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iitNONTAUT | iiEq2INV | iiEq2ISO) : 0;
            }
            /* f) compare non-tautomeric isotopic inverted to Inverted(non-tautomeric stereo) */
            if ( !eq2taut ) {
                eq2taut = pINChI &&                    /* it is non-taut non-iso stereo */
                  (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3, 0 );
                                 /* stereo-inv   isotopic    non-taut =  Inv(non-taut stereo) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iitNONTAUT | iiEq2INV | iiEq2NONTAUT) : 0;
            }
            /* g) compare non-tautomeric isotopic inverted to Inverted(non-tautomeric isotopic stereo) */
            if ( !eq2taut ) {
                eq2taut = pINChI &&                    /* it is non-taut non-iso stereo */
                  (Stereo = pINChI->StereoIsotopic) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo, EQL_SP3, 0 );
                                 /* stereo-inv    isotopic  non-taut =   Inv( iso non-taut stereo) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iitNONTAUT | iiEq2INV | iiEq2ISO | iiEq2NONTAUT) : 0;
            }
#if ( FIX_EMPTY_LAYER_BUG == 1 )
            if ( !eq2taut && pINChI && !((Stereo = pINChI->StereoIsotopic) &&
                Eql_INChI_Stereo( Stereo, EQL_SP3_INV, NULL, EQL_EXISTS, 0 )) ) {
                 /* component has no stereo; check whether it has stereo in the preceding layers */
                if ( pINChI_Taut && (Stereo_Taut = pINChI_Taut->Stereo) && /* F is not empty */
                     Eql_INChI_Stereo( Stereo_Taut, EQL_SP3_INV, NULL, EQL_EXISTS, 0 ) ||
                    !(pINChI_Taut && (Stereo_Taut = pINChI_Taut->Stereo) &&  /* M is empty and ... */
                       Eql_INChI_Stereo( Stereo_Taut, EQL_SP3_INV, NULL, EQL_EXISTS, 0 )) &&
                     (pINChI_Taut && (Stereo_Taut = pINChI_Taut->StereoIsotopic) &&  /* ... MI is not empty */
                       Eql_INChI_Stereo( Stereo_Taut, EQL_SP3_INV, NULL, EQL_EXISTS, 0 )) ) {

                    eq2taut = iiEmpty; /* the component has stereo in the preceding layer  */
                }
            }
#endif
        } else
        /*========= if not bSecondNonTautPass then compare inv taut stereo to various stereo ========*/
        if ( !bSecondNonTautPass && bOmitRepetitions && pINChI &&
               (pINChI->nNumberOfIsotopicAtoms > 0 ||
                pINChI->nNumberOfIsotopicTGroups > 0 ||
                pINChI->nPossibleLocationsOfIsotopicH && pINChI->nPossibleLocationsOfIsotopicH[0] > 1) ) {
            /* compare tautomeric isotopic stereo-inverted to:
             *    a) tautomeric stereo-inverted
             *    b) Inverted(tautomeric stereo)
             *    c) Inverted(tautomeric isotopic stereo)
             */
            /* a) compare tautomeric isotopic stereo-inverted to tautomeric stereo-inverted */
            if ( !eq2taut ) {
                eq2taut = pINChI &&
                  (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3_INV, 0 );
                                 /* stereo-inv  isotopic taut =  taut stereo-inv */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO  ) : 0;
            }
            /* b) compare tautomeric isotopic stereo-inverted to Inverted(tautomeric stereo) */
            if ( !eq2taut ) {
                eq2taut = pINChI &&
                  (Stereo = pINChI->StereoIsotopic) && (Stereo_Taut = pINChI->Stereo) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Taut, EQL_SP3, 0 );
                                 /* stereo-inv   isotopic taut =  Inv(taut stereo) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiEq2INV ) : 0;
            }
            /* c) compare tautomeric isotopic stereo-inverted to Inverted(tautomeric isotopic stereo) */
            if ( !eq2taut ) {
                eq2taut = pINChI &&
                  (Stereo = pINChI->StereoIsotopic) &&
                  Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo, EQL_SP3, 0 );
                                 /* stereo-inv   isotopic taut =  Inv(taut iso stereo) */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiEq2INV | iiEq2ISO ) : 0;
            }
#if ( FIX_EMPTY_LAYER_BUG == 1 )
            if ( !eq2taut && pINChI && !((Stereo = pINChI->StereoIsotopic) &&
                 Eql_INChI_Stereo( Stereo, EQL_SP3_INV, NULL, EQL_EXISTS, 0 ) ) ) {
                /* component has no MI stereo; check whether it has stereo in the preceding layer M */
                if ( (Stereo_Taut = pINChI->Stereo) &&
                     Eql_INChI_Stereo( Stereo_Taut, EQL_SP3_INV, NULL, EQL_EXISTS, 0 ) ) {
                    eq2taut = iiEmpty; /* the component has stereo in the preceding layer  */
                }
            }
#endif
        }
        if ( eq2taut ) {
            /* we may be here only in case of the current layer found equal in another layer the same component */
            if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                /* previous component exists; output it before output the current component */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( (Stereo_Prev = pINChI_Prev->StereoIsotopic) && Stereo_Prev->nNumberOfStereoCenters > 0 ) {
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                    tot_len += MakeStereoString( Stereo_Prev->nNumber, NULL, Stereo_Prev->t_parityInv,
                                                 0, Stereo_Prev->nNumberOfStereoCenters,
                                                 pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                }
            } else
            if ( pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                /* do not output stereo of non-tautomeric in non-taut layer: it has been output in the main layer */
            }
            /* we have found another (previously printed) layer of the current component equal to this layer */
            /* output this (current) equivalence mark = EquString(eq2taut) */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
            pINChI_Prev      = NULL; /* pINChI_Prev sp2 does not exist since */
            pINChI_Taut_Prev = NULL; /* pINChI has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;     /* pINChI_Prev and pINChI_Taut_Prev have already been output */
        } else 
        if ( eq2tautPrev ) {
            /* at this point pINChI_Prev does not exist; however, pINChI */
             /*might have been discovered and it is different from pINChI_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Prev      = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0;
        } else {
            /* current layer is different from previously printed layers of the current component */
            /* compare the current layer to this layer of the previous component: */
            /* check whether pINChI and pINChI_Prev have non-zero identical stereo sp2 */
            /*================ compare iso sp3 to previous =====================*/
            eq2prev =bUseMulipliers &&
                     pINChI && pINChI->nNumberOfIsotopicAtoms + pINChI->nNumberOfIsotopicTGroups > 0 &&
                     pINChI_Prev && pINChI_Prev->nNumberOfIsotopicAtoms + pINChI_Prev->nNumberOfIsotopicTGroups > 0 &&
                     /* do both have stereo? */
                     (Stereo = pINChI->StereoIsotopic) && (Stereo_Prev = pINChI_Prev->StereoIsotopic) &&
                     /* is their inverted stereo same? */
                     Eql_INChI_Stereo( Stereo, EQL_SP3_INV, Stereo_Prev, EQL_SP3_INV, 0 );
            if ( eq2prev ) {
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms && pINChI_Prev->nNumberOfIsotopicAtoms + pINChI_Prev->nNumberOfIsotopicTGroups > 0 ) {
                    if ( (Stereo_Prev = pINChI_Prev->StereoIsotopic) &&
                          Stereo_Prev->nNumberOfStereoCenters > 0 && Stereo_Prev->nCompInv2Abs ) {
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);

                        tot_len += MakeStereoString( Stereo_Prev->nNumberInv, NULL, Stereo_Prev->t_parityInv,
                                                     0, Stereo_Prev->nNumberOfStereoCenters,
                                                     pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                    }
                    /* else sp3 info is not present in pINChI_Prev */
                } else
                /* do not print pINChI_Prev because it either do not exist of have already been printed */
                if ( bSecondNonTautPass && pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms ) {
                     if ( (Stereo_Taut_Prev = pINChI_Taut_Prev->StereoIsotopic) &&
                           Stereo_Taut_Prev->nNumberOfStereoCenters > 0 && Stereo_Taut_Prev->nCompInv2Abs ) {
                        /* since pINChI_Prev does not exist, pINChI_Taut_Prev is non-tautomeric */
                        /* and it has non-trivial inv sp3 info. It has already been printed in the main section */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                        ;/* pINChI_Taut_Prev sp3 info was output in the main stereo section */
                     } else {
                        ; /* pINChI_Taut_Prev exists and has not sp3 info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Prev = pINChI;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}
/***************************************************************************/
int str_AuxInvIsoSp3Numb(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is0 /*, *is2*/;
    INChI        *pINChI,  *pINChI_Taut;
    INChI_Aux    *pINChI_Aux, *pINChI_Aux_Prev, *pINChI_Aux_Taut;
    INChI_Stereo *Stereo, *Stereo_Taut;
    int          eq2taut, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    /**************************************************
     * specificity of numbering: there is no previous *
     * component because no repetition is possible    *
     **************************************************/
    pINChI          = NULL;
    pINChI_Taut     = NULL;
    pINChI_Aux      = NULL;
    pINChI_Aux_Taut = NULL;
    pINChI_Aux_Prev = NULL;
    bNext       = 0;
    is          = NULL;
   /* is2         = NULL;*/
    is0         = pINChISort;
   /* is20        = bSecondNonTautPass? pINChISort2 : NULL;*/
    eq2taut     = 0; /* may be non-zero if another layer of the current component = current layer */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i < num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        is=is0+i;
        pINChI     = (0 <= (ii=GET_II(bOutType,is)))? is->pINChI[ii] : NULL;
        pINChI_Aux = pINChI? is->pINChI_Aux[ii] : NULL;
        /*================ to compare to previously printed =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was printed on the 1st pass */
            pINChI_Taut     = (0 <= (ii2=GET_II(OUT_T1,is)))? is->pINChI[ii2] : NULL;
            pINChI_Aux_Taut = pINChI_Taut? is->pINChI_Aux[ii2] : NULL;
        }
        eq2taut = 0;
        /*========= if bSecondNonTautPass then compare iso non-taut stereo to other stereo ========*/
        if ( bSecondNonTautPass && bOmitRepetitions && pINChI && pINChI_Aux && pINChI_Aux->bIsIsotopic &&
             (Stereo = pINChI->StereoIsotopic) && Stereo->nCompInv2Abs &&
             pINChI_Aux->nNumberOfAtoms > 0 && pINChI_Aux->nIsotopicOrigAtNosInCanonOrdInv ) {
            /* compare isotopic non-tautomeric inverted stereo numbering to:
             *   a) tautomeric numbering
             *   b) non-tautomeric numbering
             *   c) *tautomeric isotopic numbering
             *   d) *non-tautomeric isotopic numbering
             *   e) tautomeric inverted stereo numbering
             *   f) *non-tautomeric inverted stereo numbering
             *   g) tautomeric isotopic inverted stereo numbering
             */
            /* a) compare isotopic non-tautomeric inverted stereo numbering to tautomeric numbering */
            if ( !eq2taut ) {
                eq2taut = pINChI_Taut &&
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux_Taut, EQL_NUM );
                                 /* stereo-inv   isotopic numbering  non-taut =  taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiNUMB | iitNONTAUT ) : 0;
            }
            /* b) compare isotopic non-tautomeric inverted stereo numbering to non-tautomeric numbering */
            if ( !eq2taut ) {
                eq2taut =
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux, EQL_NUM );
                                 /* stereo-inv    isotopic   numb.    non-taut =  non-taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO  | iiNUMB | iitNONTAUT | iiEq2NONTAUT ) : 0;
            }
            /* c) compare isotopic non-tautomeric inverted stereo numbering to tautomeric isotopic numbering */
            if ( !eq2taut ) {
                eq2taut = pINChI_Taut &&
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux_Taut, EQL_NUM_ISO );
                                 /* stereo-inv   isotopic   numb.     non-taut =  taut iso numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiNUMB | iitNONTAUT | iiEq2ISO ) : 0;
            }
            /* d) compare isotopic non-tautomeric inverted stereo numbering to non-tautomeric isotopic numbering */
            if ( !eq2taut ) {
                eq2taut = Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux, EQL_NUM_ISO );
                                 /* stereo-inv   isotopic   numb.     non-taut =  non-taut isotopic numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiNUMB | iitNONTAUT | iiEq2NONTAUT | iiEq2ISO) : 0;
            }
            /* e) compare isotopic non-tautomeric inverted stereo numbering to tautomeric inverted stereo numbering */
            if ( !eq2taut ) {
                eq2taut = pINChI_Taut && pINChI_Aux_Taut &&
                  (Stereo_Taut = pINChI_Taut->Stereo) && Stereo_Taut->nCompInv2Abs &&
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux_Taut, EQL_NUM_INV );
                                 /* stereo-inv   isotopic numbering  non-taut =  stereo-inv taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiNUMB | iitNONTAUT | iiEq2INV) : 0;
            }
            /* f) compare isotopic non-tautomeric inverted stereo numbering to non-tautomeric inverted stereo numbering */
            if ( !eq2taut ) {
                eq2taut =
                  (Stereo_Taut = pINChI->StereoIsotopic) && Stereo_Taut->nCompInv2Abs &&
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux, EQL_NUM_INV );
                                 /* stereo-inv   isotopic numbering  non-taut =  stereo-inv non-taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiNUMB | iitNONTAUT | iiEq2INV | iiEq2NONTAUT) : 0;
            }
            
            /* g) compare isotopic non-tautomeric inverted stereo numbering to tautomeric isotopic inverted stereo numbering */
            if ( !eq2taut ) {
                eq2taut = pINChI_Taut &&
                  (Stereo_Taut = pINChI_Taut->StereoIsotopic) && Stereo_Taut->nCompInv2Abs &&
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux_Taut, EQL_NUM_INV | EQL_NUM_ISO );
                                 /* stereo-inv   isotopic numbering  non-taut =  stereo-inv iso taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiNUMB | iitNONTAUT | iiEq2INV | iiEq2ISO) : 0;
            }
        } else
        /*========= if not bSecondNonTautPass then compare inv taut stereo numb to taut numb ========*/
        if ( !bSecondNonTautPass && bOmitRepetitions && pINChI && pINChI_Aux && pINChI_Aux->bIsIsotopic &&
             (Stereo = pINChI->StereoIsotopic) && Stereo->nCompInv2Abs &&
             pINChI_Aux->nNumberOfAtoms > 0 && pINChI_Aux->nIsotopicOrigAtNosInCanonOrdInv ) {
            /* compare isotopic tautomeric inverted stereo numbering to:
             *   a) tautomeric numbering
             *   b) tautomeric isotopic numbering
             *   c) tautomeric inverted stereo numbering
             */
            /* a) compare isotopic tautomeric inverted stereo numbering to tautomeric numbering */
            if ( !eq2taut ) {
                eq2taut = Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux, EQL_NUM );
                                 /* stereo-inv   isotopic numbering  (taut) =  taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiNUMB ) : 0;
            }
            /* b) compare isotopic tautomeric inverted stereo numbering to tautomeric isotopic numbering */
            if ( !eq2taut ) {
                eq2taut = Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux, EQL_NUM_ISO );
                                 /* stereo-inv   isotopic numbering(taut) =  isotopic taut numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiNUMB | iiEq2ISO ) : 0;
            }
            /* b) compare isotopic tautomeric inverted stereo numbering to tautomeric inverted stereo numbering */
            if ( !eq2taut ) {
                eq2taut = (Stereo_Taut = pINChI->Stereo) && Stereo->nCompInv2Abs &&
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM_INV | EQL_NUM_ISO, pINChI_Aux, EQL_NUM_INV );
                                 /* stereo-inv   isotopic numbering  (taut) =  taut stereo-inv numbering */
                eq2taut = eq2taut? (iiSTEREO_INV | iitISO | iiNUMB | iiEq2INV ) : 0;
            }
        }
        if ( eq2taut ) {
            /* we have found another (previously printed) layer of the current component equal to this layer */
            /* output this (current) equivalence mark = EquString(eq2taut) */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
        } else {
            /* current layer is different from previously printed layers of the current component */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            if ( bNext ++ ) {
                tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI && pINChI_Aux && pINChI_Aux->bIsIsotopic && pINChI_Aux->nNumberOfAtoms &&
                 (Stereo = pINChI->StereoIsotopic) && Stereo->nNumberOfStereoCenters &&
                 Stereo->nCompInv2Abs && pINChI_Aux->nIsotopicOrigAtNosInCanonOrdInv ) {
                    tot_len += MakeCtString( pINChI_Aux->nIsotopicOrigAtNosInCanonOrdInv,
                                             pINChI_Aux->nNumberOfAtoms, 0, NULL, 0,
                                             pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
            }
            /* else isotopic inv stereo info is not present in pINChI */
        }
    }
    if ( multPrevEquStr && pPrevEquStr ) {
        /* the new EqStr of the last item has not been printed; output it now */
        if ( bNext ++ ) {
            tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
        }
        tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
        pPrevEquStr = NULL;
        multPrevEquStr = 0;
    }
    return tot_len;
}
/***************************************************************************/
int str_HillFormula(INCHI_SORT *pINChISort, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int num_components, int bUseMulipliers)
{
    int          i, ii;
    INCHI_SORT   *is, *is0;
    INChI        *pINChI,  *pINChI_Prev;
    int          mult, eq2prev, bNext;

    if ( !(is0 = pINChISort) ) {
        return tot_len;
    }
    i  = 0;
    pINChI_Prev = (0 <= (ii=GET_II(bOutType,is0)))? is0->pINChI[ii] : NULL;
    mult       = 0;
    bNext      = 0;
    for ( i++; i <= num_components; i ++ ) {
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        eq2prev = bUseMulipliers &&
                  pINChI && pINChI_Prev && pINChI->szHillFormula && pINChI_Prev->szHillFormula &&
                  pINChI->szHillFormula[0] && !strcmp(pINChI_Prev->szHillFormula, pINChI->szHillFormula);
        if ( eq2prev ) {
            mult ++; /* mult = (number of non-empty equal items)-1 */
            continue;
        } else {
            if ( bNext ++ ) {
                tot_len += MakeDelim( ".", pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI_Prev && pINChI_Prev->szHillFormula && pINChI_Prev->szHillFormula[0] ) {
                tot_len += MakeMult(  mult+1, "", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                tot_len += MakeHillFormulaString( pINChI_Prev->szHillFormula, pStr + tot_len,
                                                 nStrLen-tot_len, bOverflow);
            }
        }
        pINChI_Prev = pINChI;
        mult = 0; /* we do not know whether the item is empty */
    }
    return tot_len;
}
/***************************************************************************/
int str_HillFormula2(INCHI_SORT *pINChISort /* non-taut */, INCHI_SORT *pINChISort2 /* taut */,
                     char *pStr, int nStrLen, int tot_len,
                     int *bOverflow, int bOutType, int num_components, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI,  *pINChI_Prev, *pINChI_Taut, *pINChI_Taut_Prev;
    int          mult, eq2prev, bNext, bEqToTaut, tot_len_inp = tot_len;

    is   = NULL;
    is2  = NULL;
    is0  = pINChISort;
    is20 = pINChISort2;
    i  = 0;

    pINChI_Prev      = (0 <= (ii=GET_II(bOutType,is0)))? is0->pINChI[ii] : NULL;
    pINChI_Taut_Prev = (0 <= (ii2=GET_II(OUT_T1,is20)))? is20->pINChI[ii2] : NULL;
    mult       = 0;
    bNext      = 0;
    bEqToTaut  = 1;
    bEqToTaut = bEqToTaut &&
                pINChI_Prev && pINChI_Taut_Prev && !pINChI_Taut_Prev->bDeleted &&
                pINChI_Prev->szHillFormula && pINChI_Taut_Prev->szHillFormula &&
                !strcmp(pINChI_Prev->szHillFormula, pINChI_Taut_Prev->szHillFormula);
    for ( i++; i <= num_components; i ++ ) {
        pINChI      = (i < num_components && (is=is0+i, 0 <= (ii =GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        pINChI_Taut = (i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI[ii2] : NULL;
        if ( bEqToTaut && (pINChI || pINChI_Taut) ) {
            bEqToTaut = pINChI && pINChI_Taut && !pINChI_Taut->bDeleted &&
                        pINChI->szHillFormula && pINChI_Taut->szHillFormula &&
                        !strcmp(pINChI->szHillFormula, pINChI_Taut->szHillFormula);
        }
        eq2prev = bUseMulipliers &&
                  pINChI && pINChI_Prev && pINChI->szHillFormula && pINChI_Prev->szHillFormula &&
                  pINChI->szHillFormula[0] && !strcmp(pINChI_Prev->szHillFormula, pINChI->szHillFormula);
        if ( eq2prev ) {
            mult ++; /* mult = (number of non-empty equal items)-1 */
            continue;
        } else {
            if ( bNext ++ ) {
                tot_len += MakeDelim( ".", pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI_Prev && pINChI_Prev->szHillFormula && pINChI_Prev->szHillFormula[0] ) {
                tot_len += MakeMult(  mult+1, "", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                tot_len += MakeHillFormulaString( pINChI_Prev->szHillFormula, pStr + tot_len,
                                                 nStrLen-tot_len, bOverflow);
            }
        }
        pINChI_Prev = pINChI;
        mult = 0; /* we do not know whether the item is empty */
    }
    if ( bEqToTaut ) {
        pStr[tot_len=tot_len_inp] = '\0';
    }
    return tot_len;
}
/***************************************************************************/
int str_Connections(INCHI_SORT *pINChISort, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int ATOM_MODE, int num_components, int bUseMulipliers)
{
    int          i, ii;
    INCHI_SORT   *is, *is0;
    INChI        *pINChI,  *pINChI_Prev;
    int          mult, eq2prev, bNext, tot_len_inp, nNumEmpty;

    if ( !(is0 = pINChISort) ) {
        return tot_len;
    }
    i  = 0;
    pINChI_Prev = (0 <= (ii=GET_II(bOutType,is0)))? is0->pINChI[ii] : NULL;
    is          = NULL;
    mult        = 0;
    bNext       = 0;
    tot_len_inp = tot_len;
    nNumEmpty   = 0;
    for ( i++; i <= num_components; i ++ ) {
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        eq2prev = bUseMulipliers &&
                 pINChI && pINChI_Prev && pINChI->lenConnTable > 1 &&
                 pINChI_Prev->lenConnTable==pINChI->lenConnTable &&
                 !memcmp( pINChI_Prev->nConnTable, pINChI->nConnTable,
                          pINChI_Prev->lenConnTable*sizeof(pINChI->nConnTable[0]) );
        if ( eq2prev ) {
            mult ++; /* mult = (number of non-empty equal items)-1 */
            continue;
        } else
        if ( pINChI_Prev ) {
            if ( bNext ++ ) {
                tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI_Prev && pINChI_Prev->lenConnTable > 1 ) {
                tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                tot_len += MakeCtStringNew( pINChI_Prev->nConnTable, pINChI_Prev->lenConnTable, 0,
                                         NULL, pINChI_Prev->nNumberOfAtoms,
                                         pStr + tot_len, nStrLen-tot_len, ATOM_MODE, bOverflow);
            } else {
                nNumEmpty ++;
            }
        }
        pINChI_Prev = pINChI;
        mult = 0; /* we do not know whether the item is empty */
    }
    if ( nNumEmpty == num_components && tot_len > tot_len_inp ) {
        tot_len = tot_len_inp;
        pStr[tot_len] = '\0';
    }
    return tot_len;
}
/***************************************************************************/
int str_H_atoms(INCHI_SORT *pINChISort, char *pStr, int nStrLen, int tot_len,
               int *bOverflow, int bOutType, int ATOM_MODE, int TAUT_MODE,
               int num_components, int bUseMulipliers)
{
    int          i, j, ii, len_H;
    INCHI_SORT   *is, *is0;
    INChI        *pINChI,  *pINChI_Prev;
    int          mult, eq2prev, bNext, bNotEmpty, nNumEmpty, tot_len_inp;

    nNumEmpty = 0;
    tot_len_inp = tot_len;
    is0 = pINChISort;
    is  = NULL;
    i  = 0;
    pINChI_Prev = (0 <= (ii=GET_II(bOutType,is0)))? is0->pINChI[ii] : NULL;
    mult       = 0;
    bNext      = 0;
    for ( i++; i <= num_components; i ++) {
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*========== compare to previous ============*/
        eq2prev = bUseMulipliers &&
                 pINChI && pINChI_Prev && (pINChI->nNumberOfAtoms > 0 || pINChI->lenTautomer>1) &&
                 pINChI_Prev->nNumberOfAtoms==pINChI->nNumberOfAtoms &&
                 (!pINChI_Prev->nNumberOfAtoms || !memcmp( pINChI_Prev->nNum_H, pINChI->nNum_H,
                          pINChI_Prev->nNumberOfAtoms*sizeof(pINChI->nNum_H[0]) ) ) &&
                 !CompareTautNonIsoPartOfINChI( pINChI_Prev, pINChI );
                  
        if ( eq2prev && pINChI_Prev->lenTautomer <= 1 ) {
            /* make sure it is not empty */
            eq2prev = 0;
            for ( j = 0; j < pINChI_Prev->nNumberOfAtoms; j ++ ) {
                if ( pINChI_Prev->nNum_H[j] ) {
                    eq2prev = 1;
                    break;
                }
            }
        }
        if ( eq2prev ) {
            mult ++; /* mult = (number of non-empty equal items)-1 */
            continue;
        } else
        if ( pINChI_Prev ) {
            /* delimiter */
            if ( bNext ++ ) {
                tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            /* verify non-empty */
            bNotEmpty = 0;
            if ( pINChI_Prev ) {
                bNotEmpty = (pINChI_Prev->lenTautomer > 1);
                if ( !bNotEmpty ) {
                    for ( j = 0; j < pINChI_Prev->nNumberOfAtoms; j ++ ) {
                        if ( pINChI_Prev->nNum_H[j] ) {
                            bNotEmpty = 1;
                            break;
                        }
                    }
                }
            }
            if ( bNotEmpty ) {
                tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                /* H-atoms */
                tot_len += (len_H = MakeHString( 0, pINChI_Prev->nNum_H, pINChI_Prev->nNumberOfAtoms,
                                        pStr + tot_len, nStrLen-tot_len, ATOM_MODE, bOverflow ));
                /*  tautomeric groups */
                tot_len += MakeTautString( pINChI_Prev->nTautomer, pINChI_Prev->lenTautomer, (0!=len_H),
                                         pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
            } else {
                nNumEmpty ++;
            }
        }
        pINChI_Prev = pINChI;
        mult = 0; /* we do not know whether the item is empty */
    }
    if ( nNumEmpty == num_components && tot_len > tot_len_inp ) {
        tot_len = tot_len_inp;
        pStr[tot_len] = '\0';
    }
    return tot_len;
}
/***************************************************************************/
int str_Charge2(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI,  *pINChI_Prev,  *pINChI_Taut,  *pINChI_Taut_Prev;
    int         nTotalCharge, nTotalCharge_Prev, nTotalCharge_Taut, nTotalCharge_Taut_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    pINChI_Taut      = NULL;
    pINChI_Prev      = NULL;
    pINChI_Taut_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is2         = NULL;
    is0         = pINChISort;
    is20        = bSecondNonTautPass? pINChISort2 : NULL;
    eq2taut     = 0; /* may be non-zero only on the 2nd (non-taut) pass */
    eq2tautPrev = 1; /* pINChI_Prev (previous pINChI) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;     
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*================ compare sp3 to previous =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was output on the 1st pass */
            pINChI_Taut = ( i < num_components && (is2=is20+i, 0 <= (ii2=GET_II(OUT_T1,is2))))? is2->pINChI[ii2] : NULL;
        }
        /*========= if bSecondNonTautPass then compare non-iso non-taut stereo to non-iso taut ========*/
        eq2taut = 0;
        if ( !eq2taut && bSecondNonTautPass && bOmitRepetitions ) {
            eq2taut = pINChI && pINChI_Taut && !pINChI_Taut->bDeleted &&
                      (nTotalCharge = pINChI->nTotalCharge) && (nTotalCharge_Taut = pINChI_Taut->nTotalCharge) &&
                      nTotalCharge == nTotalCharge_Taut;
            eq2taut = eq2taut? (iiEQU | iitNONTAUT) : 0;
        }
        if ( eq2taut ) {
            /* we may be here only in case of the second (non-taut) pass */
            /* current non-taut stereo has been found to be same as tautomeric */
            if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                /* previous component exists; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( nTotalCharge_Prev = pINChI_Prev->nTotalCharge ) {
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                    tot_len += sprintf( pStr + tot_len, "%+d", nTotalCharge_Prev );
                }
            } else
            if ( pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms && !pINChI_Taut_Prev->bDeleted ) {
                /* previous non-taut component exists only in taut list */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
            } 
            /* we have found pINChI->nTotalCharge same as in pINChI_Taut */
            /* output this (current) equivalence as '*', that is, same as tautomeric */
            /* that was printed on the 1st pass. */

            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }

            pINChI_Prev      = NULL; /* pINChI_Prev sp2 does not exist since */
            pINChI_Taut_Prev = NULL; /* pINChI has just been printed */
            mult           = 0;
            eq2tautPrev    = 1;     /* pINChI_Prev sp2 does not exist */
        } else 
        if ( eq2tautPrev ) {
            /* at this point pINChI_Prev does not exist; however, pINChI */
             /*might have been discovered and it is different from pINChI_Taut */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Prev      = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0;
        } else {
            /* check whether pINChI and pINChI_Prev have non-zero identical stereo sp3 */
            /*================ compare sp3 to previous =====================*/
            eq2prev =bUseMulipliers &&
                     pINChI && pINChI_Prev &&
                     (nTotalCharge = pINChI->nTotalCharge) && (nTotalCharge_Prev = pINChI_Prev->nTotalCharge) &&
                     nTotalCharge == nTotalCharge_Prev;
            if ( eq2prev ) {
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Prev && pINChI_Prev->nNumberOfAtoms ) {
                    if ( nTotalCharge_Prev = pINChI_Prev->nTotalCharge ) {
                        /* pINChI_Prev exists and has charge info */
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                        tot_len += sprintf( pStr + tot_len, "%+d", nTotalCharge_Prev );
                    }
                    /* else charge is not present in pINChI_Prev */
                } else
                if ( bSecondNonTautPass && pINChI_Taut_Prev && pINChI_Taut_Prev->nNumberOfAtoms && !pINChI_Taut_Prev->bDeleted ) {
                     if ( nTotalCharge_Taut_Prev = pINChI_Taut_Prev->nTotalCharge ) {
                        /* since pINChI_Prev does not exist, pINChI_Taut_Prev is non-tautomeric */
                        /* and it has charge info. This info has already been printed in the main section */
                        /*
                        tot_len += MakeDelim( sIdenticalValues, pStr + tot_len, nStrLen-tot_len, bOverflow);
                        */
                        ; /* pINChI_Taut_Prev sp3 info was output in the main stereo section */
                     } else {
                        ; /* pINChI_Taut_Prev exists and has not sp3 info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Prev = pINChI;
            pINChI_Taut_Prev = pINChI_Taut;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}
/***************************************************************************/
int str_FixedH_atoms(INCHI_SORT *pINChISort, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int ATOM_MODE, int num_components, int bUseMulipliers)
{
    int          i, j, ii, nNumEmpty;
    INCHI_SORT   *is, *is0;
    INChI        *pINChI,  *pINChI_Prev;
    int          mult, eq2prev, bNext, bNotEmpty, tot_len_inp;

    is  = NULL;
    is0 = pINChISort;
    i  = 0;
    pINChI_Prev = (0 <= (ii=GET_II(bOutType,is0)))? is0->pINChI[ii] : NULL;
    mult       = 0;
    bNext      = 0;
    nNumEmpty  = 0;
    tot_len_inp = tot_len;
    for ( i++; i <= num_components; i ++ ) {
        /* only non-tautomeric representation of tautomeric */
        pINChI = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI[ii] : NULL;
        /*================ compare fixed H to previous =====================*/
        eq2prev =bUseMulipliers &&
                 pINChI && pINChI_Prev && pINChI->nNumberOfAtoms > 0 &&
                 pINChI_Prev->nNumberOfAtoms==pINChI->nNumberOfAtoms &&
                 !memcmp( pINChI_Prev->nNum_H_fixed, pINChI->nNum_H_fixed,
                          pINChI_Prev->nNumberOfAtoms*sizeof(pINChI->nNum_H_fixed[0]) );
        if ( eq2prev ) {
            /* make sure it is not empty */
            eq2prev = 0;
            for ( j = 0; j < pINChI_Prev->nNumberOfAtoms; j ++ ) {
                if ( pINChI_Prev->nNum_H_fixed[j] ) {
                    eq2prev = 1;
                    break;
                }
            }
        }
        if ( eq2prev ) {
            mult ++; /* mult = (number of non-empty equal items)-1 */
            continue;
        } else {
            /* print pINChI_Prev */
            /* delimiter */
            if ( bNext ++ ) {
                tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI_Prev ) {
                /* verify it is not empty */
                bNotEmpty = 0;
                for ( j = 0; j < pINChI_Prev->nNumberOfAtoms; j ++ ) {
                    if ( pINChI_Prev->nNum_H_fixed[j] ) {
                        bNotEmpty = 1;
                        break;
                    }
                }
                if ( bNotEmpty ) {
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                    /* H-atoms-fixed */
                    tot_len += MakeHString( 0, pINChI_Prev->nNum_H_fixed, pINChI_Prev->nNumberOfAtoms,
                                            pStr + tot_len, nStrLen-tot_len, ATOM_MODE, bOverflow );
                } else {
                    nNumEmpty ++;
                }
            }
        }
        pINChI_Prev = pINChI;
        mult = 0; /* we do not know whether the item is empty */
    }
    if ( nNumEmpty == num_components && tot_len > tot_len_inp ) {
        tot_len = tot_len_inp;
        pStr[tot_len] = '\0';
    }
    return tot_len;
}
/***************************************************************************/
int str_AuxNumb(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components,
              int bSecondNonTautPass, int bOmitRepetitions)
{
    int          i, ii, ii2;
    INCHI_SORT   *is, *is0 /*, *is2*/;
    INChI        *pINChI,  *pINChI_Taut=NULL;
    INChI_Aux    *pINChI_Aux, *pINChI_Aux_Taut=NULL;
    int          eq2taut, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    bNext       = 0;
    /*is2         = bSecondNonTautPass? pINChISort2 : NULL;*/
    eq2taut     = 0; /* may be non-zero if another layer of the current component = current layer */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    is          = NULL;
    if ( !(is0 = pINChISort) ) {
        return tot_len;
    }
    for ( i = 0; i < num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        is=is0+i;
        pINChI     = ( 0 <= (ii=GET_II(bOutType,is)))? is->pINChI[ii] : NULL;
        pINChI_Aux = pINChI? is->pINChI_Aux[ii] : NULL;
        /*================ to compare to previously printed =====================*/
        if ( bSecondNonTautPass ) {
            /* component that was printed on the 1st pass */
            pINChI_Taut     = (0 <= (ii2=GET_II(OUT_T1,is)))? is->pINChI[ii2] : NULL;
            pINChI_Aux_Taut = pINChI_Taut? is->pINChI_Aux[ii2] : NULL;
        }
        eq2taut = 0;
        /*========= if bSecondNonTautPass then compare iso non-taut stereo to other stereo ========*/
        if ( bSecondNonTautPass && bOmitRepetitions && pINChI && pINChI_Aux && pINChI_Aux->nNumberOfAtoms > 0 ) {
            /* compare non-tautomeric numbering to:
             *   a) tautomeric numbering
             */
            /* a) compare non-tautomeric numbering to tautomeric numbering */
            if ( !eq2taut ) {
                eq2taut = pINChI_Taut && !pINChI_Taut->bDeleted &&
                  Eql_INChI_Aux_Num( pINChI_Aux, EQL_NUM, pINChI_Aux_Taut, EQL_NUM );
                                 /* numbering  non-taut =  taut numbering */
                eq2taut = eq2taut? ( iiNUMB | iitNONTAUT ) : 0;
            }
        }
        if ( eq2taut ) {
            /* we have found another (previously printed) layer of the current component equal to this layer */
            /* output this (current) equivalence mark = EquString(eq2taut) */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
        } else {
            /* current layer is different from previously printed layers of the current component */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            if ( bNext ++ ) {
                tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI && pINChI_Aux && pINChI_Aux->nNumberOfAtoms ) {
                    tot_len += MakeCtString( pINChI_Aux->nOrigAtNosInCanonOrd,
                                             pINChI_Aux->nNumberOfAtoms, 0, NULL, 0,
                                             pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
            }
        }
    }
    if ( multPrevEquStr && pPrevEquStr ) {
        /* the new EqStr of the last item has not been printed; output it now */
        if ( bNext ++ ) {
            tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
        }
        tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
        pPrevEquStr = NULL;
        multPrevEquStr = 0;
    }
    return tot_len;
}
/***************************************************************************/
int str_AuxTgroupEqu(INCHI_SORT *pINChISort, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components, int bUseMulipliers)
{
    int          i, ii;
    INCHI_SORT   *is, *is0;
    INChI_Aux    *pINChI_Aux, *pINChI_Aux_Prev;
    int          mult, eq2prev, bNext;

    is0 = pINChISort;
    is  = NULL;
    i  = 0;
    pINChI_Aux_Prev = (0 <= (ii=GET_II(bOutType,is0)))? is0->pINChI_Aux[ii] : NULL;
    mult       = 0;
    bNext      = 0;
    for ( i++; i <= num_components; i ++ ) {
        pINChI_Aux = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI_Aux[ii] : NULL;
        eq2prev = bUseMulipliers &&
                  Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU_TG, pINChI_Aux_Prev, EQL_EQU_TG );
        if ( eq2prev ) {
            mult ++; /* mult = (number of non-empty equal items)-1 */
            continue;
        } else {
            if ( bNext ++ ) {
                tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI_Aux_Prev && pINChI_Aux_Prev->nNumberOfTGroups &&
                 bHasEquString( pINChI_Aux_Prev->nConstitEquTGroupNumbers, pINChI_Aux_Prev->nNumberOfTGroups) ) {
                tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                tot_len += MakeEquString( pINChI_Aux_Prev->nConstitEquTGroupNumbers, pINChI_Aux_Prev->nNumberOfTGroups, 0,
                                         pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
            }
        }
        pINChI_Aux_Prev = pINChI_Aux;
        mult = 0; /* we do not know whether the item is empty */
    }
    return tot_len;
}

/***************************************************************************/
int str_AuxChargeRadVal(INCHI_SORT *pINChISort, char *pStr, int nStrLen, int tot_len,
                  int *bOverflow, int bOutType, int TAUT_MODE, int num_components, int bUseMulipliers)
{
    int          i, ii;
    INCHI_SORT   *is, *is0;
    INChI_Aux    *pINChI_Aux, *pINChI_Aux_Prev;
    int          mult, eq2prev, bNext;

    pINChI_Aux_Prev = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is0         = pINChISort;
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI_Aux = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI_Aux[ii] : NULL;
        /* check whether pINChI_Aux and pINChI_Aux_Prev have identical info */
        eq2prev = bUseMulipliers &&
                  EqlOrigInfo( pINChI_Aux, pINChI_Aux_Prev );
        if ( eq2prev ) {
            /* eq. info is same and non-trivial */
            mult ++; /* mult = (number of non-empty equal items)-1 */
            continue;
        } else
        if ( i ) {
            /* pINChI_Aux info is either different or trivial. Output pINChI_Aux_Prev anyway */
            if ( bNext ++ ) {
                tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
            if ( pINChI_Aux_Prev && pINChI_Aux_Prev->nNumberOfAtoms ) {
                 if ( bHasOrigInfo( pINChI_Aux_Prev->OrigInfo, pINChI_Aux_Prev->nNumberOfAtoms ) ) {
                    /* pINChI_Aux_Prev exists and has orig. info info */
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                    tot_len += MakeCRVString( pINChI_Aux_Prev->OrigInfo, pINChI_Aux_Prev->nNumberOfAtoms, 0,
                                              pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                 } else {
                    ; /* pINChI_Aux_Prev exists and has only trivial info */
                 }
            }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
            else {
                int stop = 1;   /* <BRKPT> */
            }
#endif
        }
        pINChI_Aux_Prev      = pINChI_Aux;
        mult = 0; /* we do not know whether the item is empty */
    }
    return tot_len;
}
/******************************************************************************************/
int bin_AuxTautTrans(INCHI_SORT *pINChISort, INCHI_SORT *pINChISort2,
                      AT_NUMB **pTrans_n, AT_NUMB **pTrans_s, int bOutType, int num_components)
{
    int          i, ii, ii2, ret;
    INCHI_SORT   *is, *is2, *is0, *is20;
    INChI        *pINChI, *pINChI_Taut;
    AT_NUMB     *nTrans_n  = NULL;
    AT_NUMB     *nTrans_s = NULL;

    ret = 0;
    is0  = pINChISort;
    is20 = pINChISort2;
    /* pass 1: save new non-taut numbering */
    for ( i = 0; i < num_components; i ++ ) {
        is=is0+i;
        is2=is20+i;
        pINChI      = ( 0 <= (ii=GET_II(bOutType,is)))? is->pINChI[ii]   : NULL;
        pINChI_Taut = ( 0 <= (ii2=GET_II(OUT_T1,is2)))? is2->pINChI[ii2] : NULL;
        if ( pINChI      && pINChI->nNumberOfAtoms      > 0 &&
             pINChI_Taut && pINChI_Taut->nNumberOfAtoms > 0 &&
             /* different components save equal new ord. numbers: */
             is->ord_number != is2->ord_number ) {
            if ( (nTrans_n && nTrans_s) || 
                 (nTrans_n  = (AT_NUMB *)inchi_calloc( num_components+1, sizeof(nTrans_n[0]))) &&
                 (nTrans_s  = (AT_NUMB *)inchi_calloc( num_components+1, sizeof(nTrans_s[0]))) ) {
                /* new ordering number for original non-tautomeric component number is->ord_number */
                nTrans_n[is->ord_number] = /*nTrans_t[is2->ord_number] =*/ i+1;
            }
        }
    }
    if ( nTrans_n && nTrans_s ) {
        /* pass 2: get new taut numbering, retrieve new non-taut and save the transposition */
        for ( i = 0; i < num_components; i ++ ) {
            is=is0+i;
            is2=is20+i;
            pINChI      = ( 0 <= (ii=GET_II(bOutType,is)))? is->pINChI[ii]   : NULL;
            pINChI_Taut = ( 0 <= (ii2=GET_II(OUT_T1,is2)))? is2->pINChI[ii2] : NULL;
            if ( pINChI      && pINChI->nNumberOfAtoms      > 0 &&
                 pINChI_Taut && pINChI_Taut->nNumberOfAtoms > 0 &&
                 is->ord_number != is2->ord_number &&
                 nTrans_n[is2->ord_number] ) {
                 /* nTrans_n[is2->ord_number] is new ordering number of
                    the non-taut representation of the tautomeric component
                    that has new ord number i+1 and orig ordering number is2->ord_number.
                    Old numbers start from 0, new start from 1
                  */

                /* n = nTrans_s[t]: taut component #t is in position #n of the non-taut representation */
                nTrans_s[i+1] = nTrans_n[is2->ord_number];
            }
        }
        *pTrans_n = nTrans_n;
        *pTrans_s = nTrans_s;
        ret = 1;
    } else {
        if ( nTrans_n ) {
            inchi_free( nTrans_n );
            ret = -1;
        }
        if ( nTrans_s ) {
            inchi_free( nTrans_s );
            ret = -1;
        }
    }
    return ret;
}
/******************************************************************************************/
int str_AuxTautTrans(AT_NUMB *nTrans_n, AT_NUMB *nTrans_s, char *pStr, int nStrLen, int tot_len,
                     int *bOverflow, int TAUT_MODE, int num_components)
{
    int          i, k, len, j;

    if ( nTrans_n && nTrans_s ) {
        /* print the transposition, cycle after cycle */
        for ( i = 1; i <= num_components; i ++ ) {
            if ( nTrans_s[i] ) {
                /* get one cycle of the transposition */
                for ( j = i, len = 0; (k = nTrans_s[j]); j = k, len ++ ) {
                    nTrans_n[len] = j; /* save the transposition */
                    nTrans_s[j]   = 0; /* clear used element to avoid repetitions */
                }
                /* print one cycle of the transposition */
                tot_len += MakeDelim( "(", pStr + tot_len, nStrLen-tot_len, bOverflow);
                tot_len += MakeCtString( nTrans_n, len, 0, NULL, 0,
                                         pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                tot_len += MakeDelim( ")", pStr + tot_len, nStrLen-tot_len, bOverflow);
            }
        }
    }
    if ( nTrans_n )
        inchi_free( nTrans_n );
    if ( nTrans_s )
        inchi_free( nTrans_s );
    return tot_len;
}
/***************************************************************************/
int str_StereoAbsInv(INCHI_SORT *pINChISort, char *pStr, int nStrLen, int tot_len,
               int *bOverflow, int bOutType, int num_components)
{
    int          i, j, ii;
    INCHI_SORT   *is, *is0;
    INChI_Stereo *Stereo;
    INChI        *pINChI;

    is  = NULL;
    is0 = pINChISort;

    for ( i = 0; !*bOverflow && i < num_components; i ++ ) {
        is=is0+i;
        pINChI = (0 <= (ii=GET_II(bOutType,is)))? is->pINChI[ii] : NULL;
        if ( pINChI && (Stereo = pINChI->Stereo) && (j=Stereo->nCompInv2Abs) ) {
            tot_len += MakeDelim( j<0? "1":"0", pStr + tot_len, nStrLen-tot_len, bOverflow);
        } else {
            tot_len += MakeDelim( ".", pStr + tot_len, nStrLen-tot_len, bOverflow);
        }
    }

    return tot_len;
}
/***************************************************************************/
int str_IsoStereoAbsInv(INCHI_SORT *pINChISort, char *pStr, int nStrLen, int tot_len,
               int *bOverflow, int bOutType, int num_components)
{
    int          i, j, ii;
    INCHI_SORT   *is, *is0;
    INChI_Stereo *Stereo;
    INChI        *pINChI;

    is  = NULL;
    is0 = pINChISort;

    for ( i = 0; !*bOverflow && i < num_components; i ++ ) {
        is=is0+i;
        pINChI = (0 <= (ii=GET_II(bOutType,is)))? is->pINChI[ii] : NULL;
        if ( pINChI && (Stereo = pINChI->StereoIsotopic) && (j=Stereo->nCompInv2Abs) ) {
            tot_len += MakeDelim( j<0? "1":"0", pStr + tot_len, nStrLen-tot_len, bOverflow);
        } else {
            tot_len += MakeDelim( ".", pStr + tot_len, nStrLen-tot_len, bOverflow);
        }
    }

    return tot_len;
}
/***************************************************************************/
int str_AuxIsoTgroupEqu(INCHI_SORT *pINChISort, char *pStr, int nStrLen, int tot_len,
              int *bOverflow, int bOutType, int TAUT_MODE, int num_components, int bOmitRepetitions, int bUseMulipliers)
{
    int          i, ii;
    INCHI_SORT   *is, *is0;
    INChI_Aux    *pINChI_Aux, *pINChI_Aux_Prev;
    int          mult, eq2prev, eq2taut, eq2tautPrev, bNext;
    const char  *pPrevEquStr, *pCurrEquStr;
    int         multPrevEquStr;        
    pINChI_Aux           = NULL;
    pINChI_Aux_Prev      = NULL;
    mult        = 0;
    bNext       = 0;
    is          = NULL;
    is0         = pINChISort;
    eq2taut     = 0; /* equal to non-isotopic equivalence */
    eq2tautPrev = 1; /* pINChI_Aux_Prev (previous pINChI_Aux) does not exist */
    pPrevEquStr = NULL; /*, *pCurrEquStr;*/
    multPrevEquStr = 0;        
    for ( i = 0; i <= num_components; i ++ ) {
        /* 1st (taut) pass: bOutType=OUT_TN  ; 2nd (non-taut pass) bOutType=OUT_NT */
        pINChI_Aux = (i < num_components && (is=is0+i, 0 <= (ii=GET_II(bOutType,is))))? is->pINChI_Aux[ii] : NULL;
        /*================ compare iso non-taut equivalence info to non-iso taut ========*/
        eq2taut = 0;
        if ( bOmitRepetitions && pINChI_Aux && pINChI_Aux->bIsIsotopic ) {
            /**************************************************
             * compare isotopic tautomeric equivalence to:
             *    a) non-isotopic tautomeric
             */
            /* compare isotopic t-group equivalence to non-isotopic */
            eq2taut = Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU_TG | EQL_EQU_ISO, pINChI_Aux, EQL_EQU_TG );
                               /* equ   taut-isotopic = tautomeric, same as for isotopic atom equivalence info*/
            eq2taut = eq2taut? (iiEQU | iitISO) : 0;
        }
        if ( eq2taut ) {
            /* current isotopic t-group equivalence has been found to be same as non-isotopic */
            if ( pINChI_Aux_Prev && pINChI_Aux_Prev->nNumberOfAtoms ) {
                /* previous component exists */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( bHasEquString( pINChI_Aux_Prev->nConstitEquIsotopicTGroupNumbers, pINChI_Aux_Prev->nNumberOfTGroups) ) {
                    /* output previous component(s) equivalence since it was found to be non-trivial */
                    tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                    tot_len += MakeEquString( pINChI_Aux_Prev->nConstitEquIsotopicTGroupNumbers, pINChI_Aux_Prev->nNumberOfTGroups, 0,
                                             pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                } else {
                    ; /* pINChI_Aux_Prev exists and does not have non-trivial t-group equivalence info */
                }
            }
            /* we have found pINChI_Aux->pINChI_Aux->nConstitEquIsotopicTGroupNumbers same as in pINChI_Aux->nConstitEquTGroupNumbers */
            pCurrEquStr = EquString(eq2taut);
            if ( multPrevEquStr && pPrevEquStr ) {
                if ( pCurrEquStr && !strcmp(pCurrEquStr, pPrevEquStr) ) {
                    multPrevEquStr ++;
                } else {
                    /* new EqStr is different; output it */
                    if ( bNext ++ ) {
                        tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    }
                    tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                    pPrevEquStr = pCurrEquStr;
                    multPrevEquStr = 1;
                }
            } else {
                pPrevEquStr = pCurrEquStr;
                multPrevEquStr = 1;
            }
            pINChI_Aux_Prev      = NULL; /* pINChI_Aux_Prev has already been output */
            mult           = 0;
            eq2tautPrev    = 1;
        } else
        if ( eq2tautPrev ) {
            /* at this point pINChI_Aux_Prev does not exist; however, pINChI_Aux */
            /* might have been discovered and it may be different from non-isotopic */
            if ( multPrevEquStr && pPrevEquStr ) {
                /* new EqStr is different; output it */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                tot_len += MakeEqStr( pPrevEquStr, multPrevEquStr, pStr + tot_len, nStrLen-tot_len, bOverflow);
                pPrevEquStr = NULL;
                multPrevEquStr = 0;
            }
            eq2tautPrev = 0;
            pINChI_Aux_Prev      = pINChI_Aux;
            mult = 0;
        } else {
            /* check whether pINChI_Aux and pINChI_Aux_Prev have identical non-trivial isotopic t-group equivalence info */
            eq2prev = bUseMulipliers && Eql_INChI_Aux_Equ( pINChI_Aux, EQL_EQU_TG | EQL_EQU_ISO, pINChI_Aux_Prev, EQL_EQU_TG | EQL_EQU_ISO );
            if ( eq2prev ) {
                /* eq. info is same and non-trivial */
                mult ++; /* mult = (number of non-empty equal items)-1 */
                continue;
            } else {
                /* pINChI_Aux eq. info is either different or trivial. Output pINChI_Aux_Prev anyway */
                if ( bNext ++ ) {
                    tot_len += MakeDelim( sCompDelim, pStr + tot_len, nStrLen-tot_len, bOverflow);
                }
                if ( pINChI_Aux_Prev && pINChI_Aux_Prev->nNumberOfAtoms ) {
                     if ( bHasEquString( pINChI_Aux_Prev->nConstitEquIsotopicTGroupNumbers, pINChI_Aux_Prev->nNumberOfTGroups) ) {
                        /* pINChI_Aux_Prev exists and has equivalence info */
                        tot_len += MakeMult(  mult+1, "*", pStr + tot_len, nStrLen-tot_len, 0, bOverflow);
                        tot_len += MakeEquString( pINChI_Aux_Prev->nConstitEquIsotopicTGroupNumbers, pINChI_Aux_Prev->nNumberOfTGroups, 0,
                                                 pStr + tot_len, nStrLen-tot_len, TAUT_MODE, bOverflow);
                     } else {
                        ; /* pINChI_Aux_Prev exists and has only trivial equivalence info */
                     }
                }
#if( bRELEASE_VERSION != 1 && defined(_DEBUG) )
                else {
                    int stop = 1;   /* <BRKPT> */
                }
#endif
            }
            pINChI_Aux_Prev      = pINChI_Aux;
            mult = 0; /* we do not know whether the item is empty */
        }
    }
    return tot_len;
}
