code: private void exteriorAreaInteriorPoint_(int cluster, int id_a) {
  		if (m_matrix[MatrixPredicate.ExteriorInterior] == 0)
  			return;
  
  		int clusterParentage = m_topo_graph.getClusterParentage(cluster);
  
  		if ((clusterParentage & id_a) == 0) {
  			int chain = m_topo_graph.getClusterChain(cluster);
  			int chainParentage = m_topo_graph.getChainParentage(chain);
  
  			if ((chainParentage & id_a) == 0) {
  				m_matrix[MatrixPredicate.ExteriorInterior] = 0;
  			}
  		}
  	}
docs: with the interior of Point B.