  We present a pointer-based data structure for constant time traversal of the
edges of an edge-labeled (alphabet $\Sigma$) directed hypergraph (a graph where
edges can be incident to more than two vertices, and the incident vertices are
ordered) given as hyperedge-replacement grammar $G$. It is assumed that the
grammar has a fixed rank $\kappa$ (maximal number of vertices connected to a
nonterminal hyperedge) and that each vertex of the represented graph is
incident to at most one $\sigma$-edge per direction ($\sigma \in \Sigma$).
Precomputing the data structure needs $O(|G||\Sigma|\kappa r h)$ space and
$O(|G||\Sigma|\kappa rh^2)$ time, where $h$ is the height of the derivation
tree of $G$ and $r$ is the maximal rank of a terminal edge occurring in the
grammar.
