if (!nodes_interfere(co->chordal_env, irn, other)) {
unit->nodes = xmalloc(2 * sizeof(*unit->nodes));
unit->costs = xmalloc(2 * sizeof(*unit->costs));
unit->node_count = 2;
unit->nodes[0] = irn;
unit->nodes[1] = other;
if (!nodes_interfere(co->chordal_env, irn, other)) {
unit->nodes = xmalloc(2 * sizeof(*unit->nodes));
unit->costs = xmalloc(2 * sizeof(*unit->costs));
unit->node_count = 2;
unit->nodes[0] = irn;
unit->nodes[1] = other;