computeIdealQuotient()

component_index SchreyerFrame::computeIdealQuotient ( int lev, component_index begin, component_index elem )

private

std::cout << "computeIdealQuotient(" << lev << "," << begin << "," << elem << ")" << std::endl;

Definition at line 480 of file res-schreyer-frame.cpp.

{
  // Returns the number of elements added
  res_packed_monomial m = monomial(lev, elem);
  std::vector<PreElement*> elements;
  if (ring().isSkewCommutative())
    {
      auto skewvars = new int[ring().monoid().n_vars()];
      int a = ring().monoid().skew_vars(ring().skewInfo(), m, skewvars);
      // std::cout << "adding " << a << " syz from skew" << std::endl;
      for (int i = 0; i < a; ++i)
        {
          PreElement* vp = mPreElements.allocate();
          vp->vp = mVarpowers.reserve(mMaxVPSize);
          monoid().variable_as_vp(skewvars[i], vp->vp);
          vp->degree = monoid().degree_of_vp(vp->vp);
          int len = static_cast<int>(res_varpower_monomials::length(vp->vp));
          mVarpowers.intern(len);
 
          elements.push_back(vp);
        }
      delete[] skewvars;
    }
  for (component_index i = begin; i < elem; i++)
    elements.push_back(createQuotientElement(monomial(lev, i), m));
  typedef ResF4MonomialLookupTableT<int32_t> MonomialLookupTable;
  MonomialLookupTable montab(monoid().n_vars());
 
#if 0
  std::cout << "  #pre elements = " << elements.size() << std::endl;
  for (auto i=elements.begin(); i != elements.end(); ++i)
    {
      varpower_monomials::elem_text_out(stdout, (*i)->vp);
      fprintf(stdout, "\n");
    }
#endif
  PreElementSorter C;
  std::stable_sort(elements.begin(), elements.end(), C);
 
  component_index n_elems = 0;
  for (auto i = elements.begin(); i != elements.end(); ++i)
    {
      int32_t not_used;
      bool inideal = montab.find_one_divisor_vp(0, (*i)->vp, not_used);
      if (inideal) continue;
      // Now we create a res_packed_monomial, and insert it into 'lev+1'
      montab.insert_minimal_vp(0, (*i)->vp, 0);
      res_packed_monomial monom =
          monomialBlock().allocate(monoid().max_monomial_size());
      monoid().from_varpower_monomial((*i)->vp, elem, monom);
      // Now insert it into the frame
      insertBasic(currentLevel(),
                  monom,
                  (*i)->degree + degree(currentLevel() - 1,
                                        monoid().get_component(monom)));
      n_elems++;
    }
  // std::cout << "  returns " << n_elems << std::endl;
  return n_elems;
}

References ResMemoryBlock< T, NSLAB >::allocate(), begin(), createQuotientElement(), currentLevel(), degree(), SchreyerFrameTypes::PreElement::degree, ResMonoidDense::degree_of_vp(), ExponentList< long, false >::elem_text_out(), F4MonomialLookupTableT< Key >::find_one_divisor_vp(), ResMonoidDense::from_varpower_monomial(), F4MonomialLookupTableT< Key >::insert_minimal_vp(), insertBasic(), ExponentList< myword, false >::length(), mMaxVPSize, ResPolyRing::monoid(), monoid(), monomial, monomialBlock(), mPreElements, mVarpowers, ResMonoidDense::n_vars(), ring(), ResMonoidDense::skew_vars(), ResMonoidDense::variable_as_vp(), and SchreyerFrameTypes::PreElement::vp.

Referenced by computeNextLevel().