Electronic Proceedings in Theoretical Computer Science (Jun 2011)

Separation of Test-Free Propositional Dynamic Logics over Context-Free Languages

  • Markus Latte

DOI
https://doi.org/10.4204/EPTCS.54.15
Journal volume & issue
Vol. 54, no. Proc. GandALF 2011
pp. 207 – 221

Abstract

Read online

For a class L of languages let PDL[L] be an extension of Propositional Dynamic Logic which allows programs to be in a language of L rather than just to be regular. If L contains a non-regular language, PDL[L] can express non-regular properties, in contrast to pure PDL. For regular, visibly pushdown and deterministic context-free languages, the separation of the respective PDLs can be proven by automata-theoretic techniques. However, these techniques introduce non-determinism on the automata side. As non-determinism is also the difference between DCFL and CFL, these techniques seem to be inappropriate to separate PDL[DCFL] from PDL[CFL]. Nevertheless, this separation is shown but for programs without test operators.