is_weak_member()

bool MonomialTableZZ::is_weak_member	(	mpz_srcptr	c,
		exponents_t	exp,
		int	comp ) const

Definition at line 193 of file montableZZ.cpp.

{
  // Loop through the elements of component 'comp'
  // If that exponent vector is <= 'exp', then set g (eventual gcd) (if not
  // set).
  //   else mpz(g,g,...);
  //   if mpz_divisible_p(c,g): return true
  // At the end, return false
 
  assert(comp >= 1);
  if (comp >= static_cast<int>(_head.size())) return 0;
  mon_term *head = _head[comp];
  mon_term *t;
  int i;
 
  unsigned long expmask = ~(monomial_mask(_nvars, exp));
  mpz_t g;
  bool g_is_set = false;
  for (t = head->_next; t != head; t = t->_next)
    if ((expmask & t->_mask) == 0)
      {
        bool is_div = true;
        for (i = 0; i < _nvars; i++)
          if (exp[i] < t->_lead[i])
            {
              is_div = false;
              break;
            }
        if (!is_div) continue;
        if (!g_is_set)
          {
            mpz_init_set(g, t->_coeff);
            g_is_set = true;
          }
        else
          mpz_gcd(g, g, t->_coeff);
        /* g is set */
        if (mpz_divisible_p(c, g))
          {
            mpz_clear(g);
            return true;
          }
      }
  if (g_is_set) mpz_clear(g);
  return false;
}

References MonomialTableZZ::mon_term::_coeff, MonomialTableZZ::mon_term::_lead, MonomialTableZZ::mon_term::_mask, MonomialTableZZ::mon_term::_next, _nvars, and monomial_mask().