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/******************************************************************************
* Top contributors (to current version):
* Aina Niemetz
*
* 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/c/cvc5.h>
#include <stdio.h>
int main()
{
Cvc5TermManager* tm = cvc5_term_manager_new();
Cvc5* slv = cvc5_new(tm);
// Set the logic
cvc5_set_logic(slv, "QF_SLIA");
// Produce models
cvc5_set_option(slv, "produce-models", "true");
// The option strings-exp is needed
cvc5_set_option(slv, "strings-exp", "true");
// String type
Cvc5Sort string_sort = cvc5_get_string_sort(tm);
// String constants
Cvc5Term ab = cvc5_mk_string(tm, "ab", false);
Cvc5Term abc = cvc5_mk_string(tm, "abc", false);
// String variables
Cvc5Term x = cvc5_mk_const(tm, string_sort, "x");
Cvc5Term y = cvc5_mk_const(tm, string_sort, "y");
Cvc5Term z = cvc5_mk_const(tm, string_sort, "z");
// String concatenation: x.ab.y
Cvc5Term args3[3] = {x, ab, y};
Cvc5Term lhs = cvc5_mk_term(tm, CVC5_KIND_STRING_CONCAT, 3, args3);
// String concatenation: abc.z
Cvc5Term args2[2] = {abc, z};
Cvc5Term rhs = cvc5_mk_term(tm, CVC5_KIND_STRING_CONCAT, 2, args2);
// x.ab.y = abc.z
args2[0] = lhs;
args2[1] = rhs;
Cvc5Term formula1 = cvc5_mk_term(tm, CVC5_KIND_EQUAL, 2, args2);
// Length of y: |y|
Cvc5Term args1[1] = {y};
Cvc5Term len_y = cvc5_mk_term(tm, CVC5_KIND_STRING_LENGTH, 1, args1);
// |y| >= 0
args2[0] = len_y;
args2[1] = cvc5_mk_integer_int64(tm, 0);
Cvc5Term formula2 = cvc5_mk_term(tm, CVC5_KIND_GEQ, 2, args2);
// Regular expression: (ab[c-e]*f)|g|h
args2[0] = cvc5_mk_string(tm, "c", false);
args2[1] = cvc5_mk_string(tm, "e", false);
Cvc5Term range = cvc5_mk_term(tm, CVC5_KIND_REGEXP_RANGE, 2, args2);
args1[0] = range;
Cvc5Term reg_star = cvc5_mk_term(tm, CVC5_KIND_REGEXP_STAR, 1, args1);
args1[0] = cvc5_mk_string(tm, "ab", false);
args3[0] = cvc5_mk_term(tm, CVC5_KIND_STRING_TO_REGEXP, 1, args1);
args3[1] = reg_star;
args1[0] = cvc5_mk_string(tm, "f", false);
args3[2] = cvc5_mk_term(tm, CVC5_KIND_STRING_TO_REGEXP, 1, args1);
Cvc5Term concat = cvc5_mk_term(tm, CVC5_KIND_REGEXP_CONCAT, 3, args3);
args3[0] = concat;
args1[0] = cvc5_mk_string(tm, "g", false);
args3[1] = cvc5_mk_term(tm, CVC5_KIND_STRING_TO_REGEXP, 1, args1);
args1[0] = cvc5_mk_string(tm, "h", false);
args3[2] = cvc5_mk_term(tm, CVC5_KIND_STRING_TO_REGEXP, 1, args1);
Cvc5Term r = cvc5_mk_term(tm, CVC5_KIND_REGEXP_UNION, 3, args3);
// String variables
Cvc5Term s1 = cvc5_mk_const(tm, string_sort, "s1");
Cvc5Term s2 = cvc5_mk_const(tm, string_sort, "s2");
// String concatenation: s1.s2
args2[0] = s1;
args2[1] = s2;
Cvc5Term s = cvc5_mk_term(tm, CVC5_KIND_STRING_CONCAT, 2, args2);
// s1.s2 in (ab[c-e]*f)|g|h
args2[0] = s;
args2[1] = r;
Cvc5Term formula3 = cvc5_mk_term(tm, CVC5_KIND_STRING_IN_REGEXP, 2, args2);
// Make a query
args3[0] = formula1;
args3[1] = formula2;
args3[2] = formula3;
Cvc5Term q = cvc5_mk_term(tm, CVC5_KIND_AND, 3, args3);
// check sat
Cvc5Term assumptions[1] = {q};
Cvc5Result result = cvc5_check_sat_assuming(slv, 1, assumptions);
printf("cvc5 reports: %s is %s.\n",
cvc5_term_to_string(q),
cvc5_result_to_string(result));
if (cvc5_result_is_sat(result))
{
printf(" x = %s\n", cvc5_term_to_string(cvc5_get_value(slv, x)));
printf(" s1.s2 = %s\n", cvc5_term_to_string(cvc5_get_value(slv, s)));
}
cvc5_delete(slv);
cvc5_term_manager_delete(tm);
}
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