Function idModulo

kernel/ideals.cc:2422–2519

2 * represents (h1+h2)/h2=h1/(h1 intersect h2) */ ideal idModulo (ideal h2,ideal h1)

*/
//ideal idModulo (ideal h2,ideal h1)
ideal idModulo (ideal h2,ideal h1, tHomog hom, intvec ** w, matrix *T, GbVariant alg)
{
#ifdef HAVE_SHIFTBBA
  if (rIsLPRing(currRing))
    return idModuloLP(h2,h1,hom,w,T,alg);
#endif
  intvec *wtmp=NULL;
  if (T!=NULL) idDelete((ideal*)T);

  int i,flength=0,slength,length;

  if (idIs0(h2))
    return idFreeModule(si_max(1,h2->ncols));
  if (!idIs0(h1))
    flength = id_RankFreeModule(h1,currRing);
  slength = id_RankFreeModule(h2,currRing);
  length  = si_max(flength,slength);
  BOOLEAN inputIsIdeal=FALSE;
  if (length==0)
  {
    length = 1;
    inputIsIdeal=TRUE;
  }
  if ((w!=NULL)&&((*w)!=NULL))
  {
    //Print("input weights:");(*w)->show(1);PrintLn();
    int d;
    int k;
    wtmp=new intvec(length+IDELEMS(h2));
    for (i=0;i<length;i++)
      ((*wtmp)[i])=(**w)[i];
    for (i=0;i<IDELEMS(h2);i++)
    {
      poly p=h2->m[i];
      if (p!=NULL)
      {
        d = p_Deg(p,currRing);
        k= pGetComp(p);
        if (slength>0) k--;
        d +=((**w)[k]);
        ((*wtmp)[i+length]) = d;
      }
    }
    //Print("weights:");wtmp->show(1);PrintLn();
  }
  ideal s_temp1;
  ring orig_ring=currRing;
  ring syz_ring=rAssure_SyzOrder(orig_ring, TRUE);
  rSetSyzComp(length,syz_ring);
  {
    rChangeCurrRing(syz_ring);
    ideal s1,s2;

    if (syz_ring != orig_ring)
    {
      s1 = idrCopyR_NoSort(h1, orig_ring, syz_ring);
      s2 = idrCopyR_NoSort(h2, orig_ring, syz_ring);
    }