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