createOverlapPoly() [1/2]

auto NCGroebner::createOverlapPoly ( const FreeAlgebra & A, const PolyList & polyList, int polyIndex1, int polyIndex2, int overlapIndex )->Poly *

static

Definition at line 351 of file NCGroebner.cpp.

{
  // here, polyIndex1 and 2 are indices into polyList, and overlapIndex
  // is the index where the overlap starts in the polynomial pointed in
  // by *polyIndex1*.
  Poly* result = new Poly;
  Poly tmp1, tmp2;
  Word prefix, suffix;
  prefix = A.lead_word_prefix(*polyList[polyIndex1], overlapIndex);
  suffix = A.lead_word_suffix(*polyList[polyIndex2], *(polyList[polyIndex1]->cbegin().monom().begin()) - A.monoid().numWeights() - 1 - overlapIndex);
  A.mult_by_term_right(tmp1, *polyList[polyIndex1], A.coefficientRing()->from_long(1), suffix);
  A.mult_by_term_left(tmp2, *polyList[polyIndex2], A.coefficientRing()->from_long(1), prefix);
  A.subtract(*result, tmp1, tmp2);
  return result;
}

References begin(), prefix(), result(), and suffix().

Referenced by computeHomogeneous(), computeInhomogeneous(), createOverlapPoly(), and TEST().