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/******************************************************************************
* Top contributors (to current version):
* Aina Niemetz, Tianyi Liang, Mathias Preiner
*
* 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 via the C++ API.
*/
#include <cvc5/cvc5.h>
#include <iostream>
using namespace cvc5;
int main()
{
TermManager tm;
Solver slv(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");
// String type
Sort string = tm.getStringSort();
// std::string
std::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(Kind::STRING_CONCAT, {x, ab, y});
// String concatenation: abc.z
Term rhs = tm.mkTerm(Kind::STRING_CONCAT, {abc, z});
// x.ab.y = abc.z
Term formula1 = tm.mkTerm(Kind::EQUAL, {lhs, rhs});
// Length of y: |y|
Term leny = tm.mkTerm(Kind::STRING_LENGTH, {y});
// |y| >= 0
Term formula2 = tm.mkTerm(Kind::GEQ, {leny, tm.mkInteger(0)});
// Regular expression: (ab[c-e]*f)|g|h
Term r = tm.mkTerm(
Kind::REGEXP_UNION,
{tm.mkTerm(Kind::REGEXP_CONCAT,
{tm.mkTerm(Kind::STRING_TO_REGEXP, {tm.mkString("ab")}),
tm.mkTerm(Kind::REGEXP_STAR,
{tm.mkTerm(Kind::REGEXP_RANGE,
{tm.mkString("c"), tm.mkString("e")})}),
tm.mkTerm(Kind::STRING_TO_REGEXP, {tm.mkString("f")})}),
tm.mkTerm(Kind::STRING_TO_REGEXP, {tm.mkString("g")}),
tm.mkTerm(Kind::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(Kind::STRING_CONCAT, {s1, s2});
// s1.s2 in (ab[c-e]*f)|g|h
Term formula3 = tm.mkTerm(Kind::STRING_IN_REGEXP, {s, r});
// Make a query
Term q = tm.mkTerm(Kind::AND, {formula1, formula2, formula3});
// check sat
Result result = slv.checkSatAssuming(q);
std::cout << "cvc5 reports: " << q << " is " << result << "." << std::endl;
if(result.isSat())
{
std::cout << " x = " << slv.getValue(x) << std::endl;
std::cout << " s1.s2 = " << slv.getValue(s) << std::endl;
}
}
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