A Generic Framework for Checking Semantic Equivalences between Pushdown Automata and Finite-State Automata

by Antonín Kučera, Richard Mayr, A full version of the paper presented at IFIP TCS 2004. April 2004, 38 pages.

FIMU-RS-2004-01. Available as Postscript, PDF.

Abstract:

We propose a generic method for deciding semantic equivalences between pushdown automata and finite-state automata. The abstract part of the method is applicable to every process equivalence which is a right PDA congruence. Practical usability of the method is demonstrated on selected equivalences which are conceptual representatives of the whole spectrum. In particular, special attention is devoted to bisimulation-like equivalences (including weak, early, delay, branching, and probabilistic bisimilarity), and it is also shown how the method applies to simulation-like and trace-like equivalences. The generality does not lead to the loss of efficiency; the algorithms obtained by applying our method are essentially time-optimal and sometimes even polynomial. The list of particular results obtained by our method includes items which are first of their kind.