# Complexity of E0L Structural Equivalence

@article{Salomaa1995ComplexityOE, title={Complexity of E0L Structural Equivalence}, author={Kai Salomaa and Derick Wood and Sheng Yu}, journal={RAIRO Theor. Informatics Appl.}, year={1995}, volume={29}, pages={471-485} }

We show that the EOL structural equivalence problem is logspace hard for deterministic exponential time. Also, we show that this question can be solved in linear space by a synchronized alternating Turing machine, and thus establish an exponential space upper bound for its complexity. The equivalence of finite tree automata is shown to be logspace reducible to context-free structural equivalence. The converse reduction is well known and thus context-free structural equivalence is complete for…

## 4 Citations

On Computational Complexity of Basic Decision Problems of Finite Tree Automata

- Mathematics
- 1997

This report focuses on the following basic decision problems of nite tree automata: nonemptiness and intersection nonemptiness. There is a comprehensive proof of EXPTIME-completeness of the…

Structural Equivalence and Et0l Grammars X Structural Equivalence and Et0l Grammars 1

- Linguistics
- 1996

For a given context-sensitive grammar G we construct ET0L grammars G 1 and G 2 that are structurally equivalent if and only if the language generated by G is empty, which implies that structural…

On Simultaneous Rigid E-Unification

- Mathematics
- 1997

Automated theorem proving methods in classical logic with equality that are based on the Herbrand theorem, reduce to a problem called Simultaneous Rigid E-Unification, or SREU for short. Recent dev…

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