reduce_minimal()

void res2_comp::reduce_minimal ( int x, res2term *& f, VECTOR(res2_pair *)& elems, VECTOR(res2term *)& stripped ) const

private

Definition at line 2091 of file res-a0.cpp.

{
  // Reduce any components of 'f' that correspond to non minimal syzygies.
  monomial MINIMAL_mon = ALLOCATE_MONOMIAL(monom_size);
  const res2term *tm;
 
  for (int i = x - 1; i >= 0; i--)
    {
      res2_pair *p = elems[i];
      if (p->syz_type == SYZ2_NOT_MINIMAL)
        while ((tm = R->component_occurs_in(p->pivot_term->comp, f)) != nullptr)
          {
            // Subtract the proper multiple to f.  f = ... + c m e_y + ...
            // and                                 p = ... + d n e_y
            // where n|m.  So we want to compute f -= c/d m/n p.
            ring_elem c =
                K->divide(tm->coeff, p->pivot_term->coeff);  // exact division
            // MES: is the following line actually needed?
            M->divide(tm->monom, p->pivot_term->monom, MINIMAL_mon);
            if (stripped[p->me] == nullptr) stripped[p->me] = R->strip(p->syz);
            R->subtract_multiple_to(f, c, MINIMAL_mon, stripped[p->me]);
          }
    }
}

References ALLOCATE_MONOMIAL, res2term::coeff, K, M, res2term::monom, monom_size, monomial, p, R, SYZ2_NOT_MINIMAL, and x.

Referenced by make_minimal().