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/******************************************************************************
* Top contributors (to current version):
* Daniel Larraz, Mudathir Mohamed, Tianyi Liang
*
* This file is part of the cvc5 project.
*
* Copyright (c) 2009-2025 by the authors listed in the file AUTHORS
* in the top-level source directory and their institutional affiliations.
* All rights reserved. See the file COPYING in the top-level source
* directory for licensing information.
* ****************************************************************************
*
* A simple demonstration of reasoning about strings with cvc5 via C++ API.
*/
import static io.github.cvc5.Kind.*;
import io.github.cvc5.*;
public class Strings
{
public static void main(String args[]) throws CVC5ApiException
{
TermManager tm = new TermManager();
Solver slv = new Solver(tm);
{
// Set the logic
slv.setLogic("QF_SLIA");
// Produce models
slv.setOption("produce-models", "true");
// The option strings-exp is needed
slv.setOption("strings-exp", "true");
// Set output language to SMTLIB2
slv.setOption("output-language", "smt2");
// String type
Sort string = tm.getStringSort();
// std::string
String str_ab = "ab";
// String constants
Term ab = tm.mkString(str_ab);
Term abc = tm.mkString("abc");
// String variables
Term x = tm.mkConst(string, "x");
Term y = tm.mkConst(string, "y");
Term z = tm.mkConst(string, "z");
// String concatenation: x.ab.y
Term lhs = tm.mkTerm(STRING_CONCAT, x, ab, y);
// String concatenation: abc.z
Term rhs = tm.mkTerm(STRING_CONCAT, abc, z);
// x.ab.y = abc.z
Term formula1 = tm.mkTerm(EQUAL, lhs, rhs);
// Length of y: |y|
Term leny = tm.mkTerm(STRING_LENGTH, y);
// |y| >= 0
Term formula2 = tm.mkTerm(GEQ, leny, tm.mkInteger(0));
// Regular expression: (ab[c-e]*f)|g|h
Term r = tm.mkTerm(REGEXP_UNION,
tm.mkTerm(REGEXP_CONCAT,
tm.mkTerm(STRING_TO_REGEXP, tm.mkString("ab")),
tm.mkTerm(REGEXP_STAR, tm.mkTerm(REGEXP_RANGE, tm.mkString("c"), tm.mkString("e"))),
tm.mkTerm(STRING_TO_REGEXP, tm.mkString("f"))),
tm.mkTerm(STRING_TO_REGEXP, tm.mkString("g")),
tm.mkTerm(STRING_TO_REGEXP, tm.mkString("h")));
// String variables
Term s1 = tm.mkConst(string, "s1");
Term s2 = tm.mkConst(string, "s2");
// String concatenation: s1.s2
Term s = tm.mkTerm(STRING_CONCAT, s1, s2);
// s1.s2 in (ab[c-e]*f)|g|h
Term formula3 = tm.mkTerm(STRING_IN_REGEXP, s, r);
// Make a query
Term q = tm.mkTerm(AND, formula1, formula2, formula3);
// check sat
Result result = slv.checkSatAssuming(q);
System.out.println("cvc5 reports: " + q + " is " + result + ".");
if (result.isSat())
{
System.out.println(" x = " + slv.getValue(x));
System.out.println(" s1.s2 = " + slv.getValue(s));
}
}
Context.deletePointers();
}
}
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