def is_BF_hypergraph(self):
        """Indicates whether the hypergraph is a BF-hypergraph.
        A BF-hypergraph consists of only B-hyperedges and F-hyperedges.
        See "is_B_hypergraph" or "is_F_hypergraph" for more details.

        :returns: bool -- True iff the hypergraph is an F-hypergraph.

        """
        for hyperedge_id in self._hyperedge_attributes:
            tail = self.get_hyperedge_tail(hyperedge_id)
            head = self.get_hyperedge_head(hyperedge_id)
            if len(tail) > 1 and len(head) > 1:
                return False
        return True
Indicates whether the hypergraph is a BF-hypergraph.
        A BF-hypergraph consists of only B-hyperedges and F-hyperedges.
        See "is_B_hypergraph" or "is_F_hypergraph" for more details.

        :returns: bool -- True iff the hypergraph is an F-hypergraph.