Publication detail

A symbolic algorithm for the case-split rule in solving word constraints with extensions

HAVLENA, V. LENGÁL, O. CHEN, Y. TURRINI, A.

Original Title

A symbolic algorithm for the case-split rule in solving word constraints with extensions

Type

journal article in Web of Science

Language

English

Original Abstract

Case split is a core proof rule in current decision procedures for the theory of string constraints. Its use is the primary cause of the state space explosion in string constraint solving, since it is the only rule that creates branches in the proof tree. Moreover, explicit handling of the case split rule may cause recomputation of the same tasks in multiple branches of the proof tree. In this paper, we propose a symbolic algorithm that significantly reduces such a redundancy. In particular, we encode a string constraint as a regular language and proof rules as rational transducers. This allows us to perform similar steps in the proof tree only once, alleviating the state space explosion. We also extend the encoding to handle arbitrary Boolean combinations of string constraints, length constraints, and regular constraints. In our experimental results, we validate that our technique works in many practical cases where other state-of-the-art solvers fail to provide an answer; our Python prototype implementation solved over 50% of string constraints that could not be solved by the other tools.

Keywords

string constraints, satisfiability modulo theories, regular model checking, Nielsen transformation, finite automata, monadic second-order logic over strings

Authors

HAVLENA, V.; LENGÁL, O.; CHEN, Y.; TURRINI, A.

Released

1. 7. 2023

ISBN

0164-1212

Periodical

JOURNAL OF SYSTEMS AND SOFTWARE

Year of study

201

Number

201

State

United States of America

Pages from

111673

Pages to

111693

Pages count

21

URL

http://dx.doi.org/10.1016/j.jss.2023.111673

BibTex

@article{BUT185153,
  author="HAVLENA, V. and LENGÁL, O. and CHEN, Y. and TURRINI, A.",
  title="A symbolic algorithm for the case-split rule in solving word constraints with extensions",
  journal="JOURNAL OF SYSTEMS AND SOFTWARE",
  year="2023",
  volume="201",
  number="201",
  pages="111673--111693",
  doi="10.1016/j.jss.2023.111673",
  issn="0164-1212",
  url="http://dx.doi.org/10.1016/j.jss.2023.111673"
}