2026-08-04T06:36:26Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:15363 2024-03-06T10:55:14Z ddc:004 open_access

Pushdown Automata and Context-Free Grammars in Bisimulation Semantics Baeten, Jos C. M. Carissimo, Cesare Luttik, Bas pushdown automaton context-free grammar bisimilarity intermediate acceptance state awareness The Turing machine models an old-fashioned computer, that does not interact with the user or with other computers, and only does batch processing. Therefore, we came up with a Reactive Turing Machine that does not have these shortcomings. In the Reactive Turing Machine, transitions have labels to give a notion of interactivity. In the resulting process graph, we use bisimilarity instead of language equivalence. Subsequently, we considered other classical theorems and notions from automata theory and formal languages theory. In this paper, we consider the classical theorem of the correspondence between pushdown automata and context-free grammars. By changing the process operator of sequential composition to a sequencing operator with intermediate acceptance, we get a better correspondence in our setting. We find that the missing ingredient to recover the full correspondence is the addition of a notion of state awareness. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Jos C. M. Baeten and Cesare Carissimo and Bas Luttik 2021 Is Part Of LIPIcs, Volume 211, 9th Conference on Algebra and Coalgebra in Computer Science (CALCO 2021) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.CALCO.2021.8 urn:nbn:de:0030-drops-153632 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CALCO.2021.8 eng https://creativecommons.org/licenses/by/4.0/legalcode