Method unmatch

gecode/int/gcc/dom-sup.hpp:600–607

  }

  forceinline void
  VarNode::unmatch(BC bc) {
    if (bc == UBC) {
      nf &= ~NF_M_UBC; ubm = nullptr;
    } else {
      nf &= ~NF_M_LBC; lbm = nullptr;
    }
  }

  forceinline Edge*
  VarNode::get_match(BC bc) const {