Departmental Papers (CIS)
Date of this Version
July 2005
Document Type
Conference Paper
Recommended Citation
Rajeev Alur, Viraj Kumar, P. Madhusudan, and Mahesh Viswanathan, "Congruences for Visibly Pushdown Languages", Lecture Notes in Computer Science: Automata, Languages and Programming 3580, 1102-1114. July 2005. http://dx.doi.org/10.1007/11523468_89
Abstract
We study congruences on words in order to characterize the class of visibly pushdown languages (VPL), a subclass of context-free languages. For any language L, we define a natural congruence on words that resembles the syntactic congruence for regular languages such that this congruence is of finite index if, and only if, L is a VPL. We then study the problem of finding canonical minimal deterministic automata for VPLs. Though VPLs in general do not have unique minimal automata, we consider a subclass of VPAs called k-module single-entry VPAs that correspond to programs with recursive procedures without input parameters, and show that the class of well-matched VPLs do indeed have unique minimal k-module single-entry automata. We also give a polynomial time algorithm that minimizes such k-module single-entry VPAs.
Subject Area
CPS Formal Methods, CPS Theory
Publication Source
Lecture Notes in Computer Science: Automata, Languages and Programming
Volume
3580
Start Page
1102
Last Page
1114
DOI
10.1007/11523468_89
Copyright/Permission Statement
The original publication is available at www.springerlink.com
Date Posted: 02 November 2005
Comments
From the 32nd International Colloquium, ICALP 2005, Lisbon, Portugal, July 11-15, 2005.