Quickstart Guide

First, create a cvc5 TermManager instance:

rmManager tm = new TermManager();

Then, create a cvc5 Solver instance:

lver solver = new Solver(tm);

To produce models and unsat cores, we have to enable the following options.

solver.setOption("produce-models", "true");
solver.setOption("produce-unsat-cores", "true");

Next we set the logic. The simplest way to set a logic for the solver is to choose "ALL" . This enables all logics in the solver. Alternatively, "QF_ALL" enables all logics without quantifiers. To optimize the solver’s behavior for a more specific logic, use the logic name, e.g. "QF_BV" or "QF_AUFBV" .

solver.setLogic("ALL");

In the following, we will define real and integer constraints. For this, we first query the solver for the corresponding sorts.

Sort realSort = tm.getRealSort();
Sort intSort = tm.getIntegerSort();

Now, we create two constants x and y of sort Real , and two constants a and b of sort Integer . Notice that these are symbolic constants, not actual values.

Term x = tm.mkConst(realSort, "x");
Term y = tm.mkConst(realSort, "y");
Term a = tm.mkConst(intSort, "a");
Term b = tm.mkConst(intSort, "b");

We define the following constraints regarding x and y :

\[(0 < x) \wedge (0 < y) \wedge (x + y < 1) \wedge (x \leq y)\]

We construct the required terms and assert them as follows:

// Formally, constraints are also terms. Their sort is Boolean.
// We will construct these constraints gradually,
// by defining each of their components.
// We start with the constant numerals 0 and 1:
Term zero = tm.mkReal(0);
Term one = tm.mkReal(1);

// Next, we construct the term x + y
Term xPlusY = tm.mkTerm(Kind.ADD, x, y);

// Now we can define the constraints.
// They use the operators +, <=, and <.
// In the API, these are denoted by ADD, LEQ, and LT.
// A list of available operators is available in:
// src/api/cpp/cvc5_kind.h
Term constraint1 = tm.mkTerm(Kind.LT, zero, x);
Term constraint2 = tm.mkTerm(Kind.LT, zero, y);
Term constraint3 = tm.mkTerm(Kind.LT, xPlusY, one);
Term constraint4 = tm.mkTerm(Kind.LEQ, x, y);

// Now we assert the constraints to the solver.
solver.assertFormula(constraint1);
solver.assertFormula(constraint2);
solver.assertFormula(constraint3);
solver.assertFormula(constraint4);

Now we check if the asserted formula is satisfiable, that is, we check if there exist values of sort Real for x and y that satisfy all the constraints.

Result r1 = solver.checkSat();

The result we get from this satisfiability check is either sat , unsat or unknown . It’s status can be queried via Result.isSat , Result.isUnsat and Result.isSatUnknown . Alternatively, it can also be printed.

System.out.println("expected: sat");
System.out.println("result: " + r1);

This will print:

expected: sat
result: sat

Now, we query the solver for the values for x and y that satisfy the constraints.

Term xVal = solver.getValue(x);
Term yVal = solver.getValue(y);

It is also possible to get values for terms that do not appear in the original formula.

Term xMinusY = tm.mkTerm(Kind.SUB, x, y);
Term xMinusYVal = solver.getValue(xMinusY);

We can convert these values to Java types.

Pair<BigInteger, BigInteger> xPair = xVal.getRealValue();
Pair<BigInteger, BigInteger> yPair = yVal.getRealValue();
Pair<BigInteger, BigInteger> xMinusYPair = xMinusYVal.getRealValue();

System.out.println("value for x: " + xPair.first + "/" + xPair.second);
System.out.println("value for y: " + yPair.first + "/" + yPair.second);
System.out.println("value for x - y: " + xMinusYPair.first + "/" + xMinusYPair.second);

Another way to independently compute the value of x - y would be to perform the (rational) arithmetic manually. However, for more complex terms, it is easier to let the solver do the evaluation.

Pair<BigInteger, BigInteger> xMinusYComputed =
    new Pair<>(xPair.first.multiply(yPair.second).subtract(xPair.second.multiply(yPair.first)),
        xPair.second.multiply(yPair.second));
BigInteger g = xMinusYComputed.first.gcd(xMinusYComputed.second);
xMinusYComputed = new Pair<>(xMinusYComputed.first.divide(g), xMinusYComputed.second.divide(g));
if (xMinusYComputed.equals(xMinusYPair))
{
  System.out.println("computed correctly");
}
else
{
  System.out.println("computed incorrectly");
}

This will print:

computed correctly

Next, we will check satisfiability of the same formula, only this time over integer variables a and b . For this, we first reset the assertions added to the solver.

solver.resetAssertions();

Next, we assert the same assertions as above, but with integers. This time, we inline the construction of terms in the assertion command.

solver.assertFormula(tm.mkTerm(Kind.LT, tm.mkInteger(0), a));
solver.assertFormula(tm.mkTerm(Kind.LT, tm.mkInteger(0), b));
solver.assertFormula(
    tm.mkTerm(Kind.LT, tm.mkTerm(Kind.ADD, a, b), tm.mkInteger(1)));
solver.assertFormula(tm.mkTerm(Kind.LEQ, a, b));

Now, we check whether the revised assertion is satisfiable.

Result r2 = solver.checkSat();

// This time the formula is unsatisfiable
System.out.println("expected: unsat");
System.out.println("result: " + r2);

This time the asserted formula is unsatisfiable:

expected: unsat
result: unsat

We can query the solver for an unsatisfiable core, that is, a subset of the assertions that is already unsatisfiable.

List<Term> unsatCore = Arrays.asList(solver.getUnsatCore());
System.out.println("unsat core size: " + unsatCore.size());
System.out.println("unsat core: ");
for (Term t : unsatCore)
{
  System.out.println(t);
}

This will print:

unsat core size: 3
unsat core:
(< 0 a)
(< 0 b)
(< (+ a b) 1)

Example

examples/api/java/QuickStart.java

  1/******************************************************************************
  2 * Top contributors (to current version):
  3 *   Mudathir Mohamed, Aina Niemetz, Daniel Larraz
  4 *
  5 * This file is part of the cvc5 project.
  6 *
  7 * Copyright (c) 2009-2025 by the authors listed in the file AUTHORS
  8 * in the top-level source directory and their institutional affiliations.
  9 * All rights reserved.  See the file COPYING in the top-level source
 10 * directory for licensing information.
 11 * ****************************************************************************
 12 *
 13 * A simple demonstration of the api capabilities of cvc5.
 14 *
 15 */
 16
 17import io.github.cvc5.*;
 18import java.math.BigInteger;
 19import java.util.ArrayList;
 20import java.util.Arrays;
 21import java.util.List;
 22
 23public class QuickStart
 24{
 25  public static void main(String args[]) throws CVC5ApiException
 26  {
 27    // Create a term manager
 28    //! [docs-java-quickstart-0 start]
 29    TermManager tm = new TermManager();
 30    //! [docs-java-quickstart-0 end]
 31    // Create a solver
 32    //! [docs-java-quickstart-1 start]
 33    Solver solver = new Solver(tm);
 34    //! [docs-java-quickstart-1 end]
 35    {
 36      // We will ask the solver to produce models and unsat cores,
 37      // hence these options should be turned on.
 38      //! [docs-java-quickstart-2 start]
 39      solver.setOption("produce-models", "true");
 40      solver.setOption("produce-unsat-cores", "true");
 41      //! [docs-java-quickstart-2 end]
 42
 43      // The simplest way to set a logic for the solver is to choose "ALL".
 44      // This enables all logics in the solver.
 45      // Alternatively, "QF_ALL" enables all logics without quantifiers.
 46      // To optimize the solver's behavior for a more specific logic,
 47      // use the logic name, e.g. "QF_BV" or "QF_AUFBV".
 48
 49      // Set the logic
 50      //! [docs-java-quickstart-3 start]
 51      solver.setLogic("ALL");
 52      //! [docs-java-quickstart-3 end]
 53
 54      // In this example, we will define constraints over reals and integers.
 55      // Hence, we first obtain the corresponding sorts.
 56      //! [docs-java-quickstart-4 start]
 57      Sort realSort = tm.getRealSort();
 58      Sort intSort = tm.getIntegerSort();
 59      //! [docs-java-quickstart-4 end]
 60
 61      // x and y will be real variables, while a and b will be integer variables.
 62      // Formally, their cpp type is Term,
 63      // and they are called "constants" in SMT jargon:
 64      //! [docs-java-quickstart-5 start]
 65      Term x = tm.mkConst(realSort, "x");
 66      Term y = tm.mkConst(realSort, "y");
 67      Term a = tm.mkConst(intSort, "a");
 68      Term b = tm.mkConst(intSort, "b");
 69      //! [docs-java-quickstart-5 end]
 70
 71      // Our constraints regarding x and y will be:
 72      //
 73      //   (1)  0 < x
 74      //   (2)  0 < y
 75      //   (3)  x + y < 1
 76      //   (4)  x <= y
 77      //
 78
 79      //! [docs-java-quickstart-6 start]
 80      // Formally, constraints are also terms. Their sort is Boolean.
 81      // We will construct these constraints gradually,
 82      // by defining each of their components.
 83      // We start with the constant numerals 0 and 1:
 84      Term zero = tm.mkReal(0);
 85      Term one = tm.mkReal(1);
 86
 87      // Next, we construct the term x + y
 88      Term xPlusY = tm.mkTerm(Kind.ADD, x, y);
 89
 90      // Now we can define the constraints.
 91      // They use the operators +, <=, and <.
 92      // In the API, these are denoted by ADD, LEQ, and LT.
 93      // A list of available operators is available in:
 94      // src/api/cpp/cvc5_kind.h
 95      Term constraint1 = tm.mkTerm(Kind.LT, zero, x);
 96      Term constraint2 = tm.mkTerm(Kind.LT, zero, y);
 97      Term constraint3 = tm.mkTerm(Kind.LT, xPlusY, one);
 98      Term constraint4 = tm.mkTerm(Kind.LEQ, x, y);
 99
100      // Now we assert the constraints to the solver.
101      solver.assertFormula(constraint1);
102      solver.assertFormula(constraint2);
103      solver.assertFormula(constraint3);
104      solver.assertFormula(constraint4);
105      //! [docs-java-quickstart-6 end]
106
107      // Check if the formula is satisfiable, that is,
108      // are there real values for x and y that satisfy all the constraints?
109      //! [docs-java-quickstart-7 start]
110      Result r1 = solver.checkSat();
111      //! [docs-java-quickstart-7 end]
112
113      // The result is either SAT, UNSAT, or UNKNOWN.
114      // In this case, it is SAT.
115      //! [docs-java-quickstart-8 start]
116      System.out.println("expected: sat");
117      System.out.println("result: " + r1);
118      //! [docs-java-quickstart-8 end]
119
120      // We can get the values for x and y that satisfy the constraints.
121      //! [docs-java-quickstart-9 start]
122      Term xVal = solver.getValue(x);
123      Term yVal = solver.getValue(y);
124      //! [docs-java-quickstart-9 end]
125
126      // It is also possible to get values for compound terms,
127      // even if those did not appear in the original formula.
128      //! [docs-java-quickstart-10 start]
129      Term xMinusY = tm.mkTerm(Kind.SUB, x, y);
130      Term xMinusYVal = solver.getValue(xMinusY);
131      //! [docs-java-quickstart-10 end]
132
133      // Further, we can convert the values to java types
134      //! [docs-java-quickstart-11 start]
135      Pair<BigInteger, BigInteger> xPair = xVal.getRealValue();
136      Pair<BigInteger, BigInteger> yPair = yVal.getRealValue();
137      Pair<BigInteger, BigInteger> xMinusYPair = xMinusYVal.getRealValue();
138
139      System.out.println("value for x: " + xPair.first + "/" + xPair.second);
140      System.out.println("value for y: " + yPair.first + "/" + yPair.second);
141      System.out.println("value for x - y: " + xMinusYPair.first + "/" + xMinusYPair.second);
142      //! [docs-java-quickstart-11 end]
143
144      // Another way to independently compute the value of x - y would be
145      // to perform the (rational) arithmetic manually.
146      // However, for more complex terms,
147      // it is easier to let the solver do the evaluation.
148      //! [docs-java-quickstart-12 start]
149      Pair<BigInteger, BigInteger> xMinusYComputed =
150          new Pair<>(xPair.first.multiply(yPair.second).subtract(xPair.second.multiply(yPair.first)),
151              xPair.second.multiply(yPair.second));
152      BigInteger g = xMinusYComputed.first.gcd(xMinusYComputed.second);
153      xMinusYComputed = new Pair<>(xMinusYComputed.first.divide(g), xMinusYComputed.second.divide(g));
154      if (xMinusYComputed.equals(xMinusYPair))
155      {
156        System.out.println("computed correctly");
157      }
158      else
159      {
160        System.out.println("computed incorrectly");
161      }
162      //! [docs-java-quickstart-12 end]
163
164      // Next, we will check satisfiability of the same formula,
165      // only this time over integer variables a and b.
166
167      // We start by resetting assertions added to the solver.
168      //! [docs-java-quickstart-13 start]
169      solver.resetAssertions();
170      //! [docs-java-quickstart-13 end]
171
172      // Next, we assert the same assertions above with integers.
173      // This time, we inline the construction of terms
174      // to the assertion command.
175      //! [docs-java-quickstart-14 start]
176      solver.assertFormula(tm.mkTerm(Kind.LT, tm.mkInteger(0), a));
177      solver.assertFormula(tm.mkTerm(Kind.LT, tm.mkInteger(0), b));
178      solver.assertFormula(
179          tm.mkTerm(Kind.LT, tm.mkTerm(Kind.ADD, a, b), tm.mkInteger(1)));
180      solver.assertFormula(tm.mkTerm(Kind.LEQ, a, b));
181      //! [docs-java-quickstart-14 end]
182
183      // We check whether the revised assertion is satisfiable.
184      //! [docs-java-quickstart-15 start]
185      Result r2 = solver.checkSat();
186
187      // This time the formula is unsatisfiable
188      System.out.println("expected: unsat");
189      System.out.println("result: " + r2);
190      //! [docs-java-quickstart-15 end]
191
192      // We can query the solver for an unsatisfiable core, i.e., a subset
193      // of the assertions that is already unsatisfiable.
194      //! [docs-java-quickstart-16 start]
195      List<Term> unsatCore = Arrays.asList(solver.getUnsatCore());
196      System.out.println("unsat core size: " + unsatCore.size());
197      System.out.println("unsat core: ");
198      for (Term t : unsatCore)
199      {
200        System.out.println(t);
201      }
202      //! [docs-java-quickstart-16 end]
203    }
204    Context.deletePointers();
205  }
206}