Showing papers on "Indexed language published in 1978"
TL;DR: Technical results are applied to obtain reductions between equivalence problems for simple deterministic tree grammars recursive program schemes and the (open) equivalence problem for DPDA's.
86 citations
TL;DR: Among other results it is shown that the membership question for languages in the class of languages generated in linear time by context-sensitive grammars is NP-complete.
Abstract: The time and space complexity of the class of languages generated in linear time by context-sensitive grammars is investigated. Among other results it is shown that the membership question for languages in the class is NP-complete.
14 citations
Journal Article•
TL;DR: Two types of branching grammars are introduced inspired from Havel's works about branching automata, which naturally define two infinite hierarchies into the family of regular, respectively, linear languages.
Abstract: Two types of branching grammars are introduced inspired from Havel's works about branching automata. They naturally define two infinite hierarchies into the family of regular, respectively, linear languages. Homomorphic characterisations of regular and linear languages >n terms of branching languages are obtained. Finally, the relations between branching grammars and contextual grammars of [5] are investigated.
2 citations