A ray cast algorithm utilizing a hierarchical acceleration structure needs to perform a tree traversal in the hierarchy. In its basic form, executing the traversal requires a stac...
The complexity of various membership problems for tree automata on compressed trees is analyzed. Two compressed representations are considered: dags, which allow to share identical...
We study caterpillar tree automata [3] that are restricted to enter any subtree at most one time (or k times). We show that, somewhat surprisingly, the deterministic one-visit aut...
Alexander Okhotin, Kai Salomaa, Michael Domaratzki
The problem of selecting nodes in unranked trees is the most basic querying problem for XML. We propose stepwise tree automata for querying unranked trees. Stepwise tree automata c...
Abstract. Since recognizable tree languages are closed under the rational operations, every regular tree expression denotes a recognizable tree language. We provide an alternative ...