Function redRing

kernel/GBEngine/kstd2.cc:945–1044

}

int redRing (LObject* h,kStrategy strat)
{
  if (strat->tl<0) return 1;
  if (h->IsNull()) return 0; // spoly is zero (can only occur with zero divisors)

  int at/*,i*/;
  long d;
  int j = 0;
  int pass = 0;
  // poly zeroPoly = NULL;

// TODO warum SetpFDeg notwendig?
  h->SetpFDeg();
  assume(h->pFDeg() == h->FDeg);
  long reddeg = h->GetpFDeg();

  h->SetShortExpVector();
  loop
  {
    j = kFindDivisibleByInT(strat, h);
    if (j < 0)
    {
      // over ZZ: cleanup coefficients by complete reduction with monomials
      postReduceByMon(h, strat);
      if(h->p == NULL)
      {
        kDeleteLcm(h);
        h->Clear();
        return 0;
      }
      if(nIsZero(pGetCoeff(h->p))) return 2;
      j = kFindDivisibleByInT(strat, h);
      if(j < 0)
      {
        if(strat->tl >= 0)
            h->i_r1 = strat->tl;
        else
            h->i_r1 = -1;
        if (h->GetLmTailRing() == NULL)
        {
          kDeleteLcm(h);
          h->Clear();
          return 0;
        }
        return 1;
      }
    }
    //printf("\nFound one: ");pWrite(strat->T[j].p);
    //enterT(*h, strat);
    ksReducePoly(h, &(strat->T[j]), NULL, NULL, NULL, strat); // with debug output
    //printf("\nAfter small red: ");pWrite(h->p);
    if (h->GetLmTailRing() == NULL)
    {
      kDeleteLcm(h);
      h->Clear();
      return 0;
    }
    h->SetShortExpVector();