reduce_lead_term_ZZ()

bool QRingInfo_ZZ::reduce_lead_term_ZZ ( Nterm *& f, const Nterm * g ) const

private

Definition at line 350 of file qring.cpp.

{
  const Monoid *M = R->getMonoid();
  const ring_elem a = f->coeff;
  const ring_elem b = g->coeff;
  ring_elem u, v, rem;
  rem = globalZZ->remainderAndQuotient(a, b, v);
  if (globalZZ->is_zero(v)) return false;
  v = globalZZ->negate(v);
  bool result = globalZZ->is_zero(rem);
  monomial MONOM1 = ALLOCATE_MONOMIAL(monom_size);
  M->divide(f->monom, g->monom, MONOM1);
  if (R->is_skew_commutative())
    {
      exponents_t EXP1 = ALLOCATE_EXPONENTS(exp_size);
      exponents_t EXP2 = ALLOCATE_EXPONENTS(exp_size);
      // We need to determine the sign
      M->to_expvector(g->monom, EXP2);
      M->to_expvector(MONOM1, EXP1);
      if (R->getSkewInfo().mult_sign(EXP1, EXP2) < 0)
        R->getCoefficients()->negate_to(v);
    }
 
  // now mult g to cancel
  ring_elem g1 = const_cast<Nterm *>(g);
  g1 = R->mult_by_term(g1, v, MONOM1);
  ring_elem f1 = f;
  R->internal_add_to(f1, g1);
  f = f1;
  return result;
}

References ALLOCATE_EXPONENTS, ALLOCATE_MONOMIAL, Monoid::divide(), QRingInfo::exp_size, globalZZ, QRingInfo::monom_size, monomial, QRingInfo::R, result(), and Monoid::to_expvector().

Referenced by normal_form().