Nested Regular Expressions Can Be Compiled to Small Deterministic Nested Word Automata

摘要

We study the problem of whether regular expressions for nested words can be compiled to small deterministic nested word automata (NWAs). In theory, we obtain a positive answer for small deterministic regular expressions for nested words. In practice of navigational path queries, nondeterministic NWAs are obtained for which NWA determinization explodes. We show that practical good solutions can be obtained by using stepwise hedge automata as intermediates.