pair_not_needed()

bool gbA::pair_not_needed ( spair * p, gbelem * m )

private

Definition at line 594 of file gb-default.cpp.

{
  /* Check the criterion: in(m) divides lcm(p).
   * If so: check if lcm(p1,m) == lcm(p)  (if so, return false)
   *        check if lcm(p2,m) == lcm(p)  (if so, return false)
   * If still here, return true.
   */
  int i, first, second;
  bool firstok;
  exponents_t mexp, lcm, p1exp, p2exp;
  if (p->type != SPAIR::SPAIR_SPAIR && p->type != SPAIR::SPAIR_RING)
    return false;
  mexp = m->lead;
  lcm = p->lcm;
  if (gbelem_COMPONENT(m) != spair_COMPONENT(p)) return false;
 
  first = p->x.pair.i;
  second = p->x.pair.j;
  p1exp = gb[first]->lead;
  p2exp =
      gb[second]->lead; /* If a ring pair, this should index into gb array */
 
  ncalls++;
  for (i = 0; i < _nvars; i++, nloops++)
    if (mexp[i] > lcm[i]) return false;
 
  firstok = false;
  for (i = 0; i < _nvars; i++)
    {
      if (mexp[i] == lcm[i]) continue;
      if (p1exp[i] == lcm[i]) continue;
      firstok = true;
      break;
    }
  if (!firstok) return false;
  for (i = 0; i < _nvars; i++)
    {
      if (mexp[i] == lcm[i]) continue;
      if (p2exp[i] == lcm[i]) continue;
      return true;
    }
  return false;
}

References _nvars, gb(), gbelem_COMPONENT(), gbA::gbelem::lead, ncalls, nloops, p, spair_COMPONENT(), SPAIR_RING, and SPAIR_SPAIR.

Referenced by remove_unneeded_pairs().