code: private void interiorPointExteriorPoint_(int cluster, int id_a, int id_b,
  			int predicate) {
  		if (m_matrix[predicate] == 0)
  			return;
  
  		int clusterParentage = m_topo_graph.getClusterParentage(cluster);
  
  		if ((clusterParentage & id_a) != 0 && (clusterParentage & id_b) == 0) {
  			m_matrix[predicate] = 0;
  		}
  	}
docs: with the exterior of Point B.