Quickstart Guide

First, create a cvc5 TermManager instance:

TermManager tm = new TermManager();

Then, create a cvc5 Solver instance:

Solver 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 * This file is part of the cvc5 project.
  3 *
  4 * Copyright (c) 2009-2026 by the authors listed in the file AUTHORS
  5 * in the top-level source directory and their institutional affiliations.
  6 * All rights reserved.  See the file COPYING in the top-level source
  7 * directory for licensing information.
  8 * ****************************************************************************
  9 *
 10 * A simple demonstration of the api capabilities of cvc5.
 11 *
 12 */
 13
 14import io.github.cvc5.*;
 15import java.math.BigInteger;
 16import java.util.ArrayList;
 17import java.util.Arrays;
 18import java.util.List;
 19
 20public class QuickStart
 21{
 22  public static void main(String args[]) throws CVC5ApiException
 23  {
 24    // Create a term manager
 25    //! [docs-java-quickstart-0 start]
 26    TermManager tm = new TermManager();
 27    //! [docs-java-quickstart-0 end]
 28    // Create a solver
 29    //! [docs-java-quickstart-1 start]
 30    Solver solver = new Solver(tm);
 31    //! [docs-java-quickstart-1 end]
 32    {
 33      // We will ask the solver to produce models and unsat cores,
 34      // hence these options should be turned on.
 35      //! [docs-java-quickstart-2 start]
 36      solver.setOption("produce-models", "true");
 37      solver.setOption("produce-unsat-cores", "true");
 38      //! [docs-java-quickstart-2 end]
 39
 40      // The simplest way to set a logic for the solver is to choose "ALL".
 41      // This enables all logics in the solver.
 42      // Alternatively, "QF_ALL" enables all logics without quantifiers.
 43      // To optimize the solver's behavior for a more specific logic,
 44      // use the logic name, e.g. "QF_BV" or "QF_AUFBV".
 45
 46      // Set the logic
 47      //! [docs-java-quickstart-3 start]
 48      solver.setLogic("ALL");
 49      //! [docs-java-quickstart-3 end]
 50
 51      // In this example, we will define constraints over reals and integers.
 52      // Hence, we first obtain the corresponding sorts.
 53      //! [docs-java-quickstart-4 start]
 54      Sort realSort = tm.getRealSort();
 55      Sort intSort = tm.getIntegerSort();
 56      //! [docs-java-quickstart-4 end]
 57
 58      // x and y will be real variables, while a and b will be integer variables.
 59      // Formally, their cpp type is Term,
 60      // and they are called "constants" in SMT jargon:
 61      //! [docs-java-quickstart-5 start]
 62      Term x = tm.mkConst(realSort, "x");
 63      Term y = tm.mkConst(realSort, "y");
 64      Term a = tm.mkConst(intSort, "a");
 65      Term b = tm.mkConst(intSort, "b");
 66      //! [docs-java-quickstart-5 end]
 67
 68      // Our constraints regarding x and y will be:
 69      //
 70      //   (1)  0 < x
 71      //   (2)  0 < y
 72      //   (3)  x + y < 1
 73      //   (4)  x <= y
 74      //
 75
 76      //! [docs-java-quickstart-6 start]
 77      // Formally, constraints are also terms. Their sort is Boolean.
 78      // We will construct these constraints gradually,
 79      // by defining each of their components.
 80      // We start with the constant numerals 0 and 1:
 81      Term zero = tm.mkReal(0);
 82      Term one = tm.mkReal(1);
 83
 84      // Next, we construct the term x + y
 85      Term xPlusY = tm.mkTerm(Kind.ADD, x, y);
 86
 87      // Now we can define the constraints.
 88      // They use the operators +, <=, and <.
 89      // In the API, these are denoted by ADD, LEQ, and LT.
 90      // A list of available operators is available in:
 91      // src/api/cpp/cvc5_kind.h
 92      Term constraint1 = tm.mkTerm(Kind.LT, zero, x);
 93      Term constraint2 = tm.mkTerm(Kind.LT, zero, y);
 94      Term constraint3 = tm.mkTerm(Kind.LT, xPlusY, one);
 95      Term constraint4 = tm.mkTerm(Kind.LEQ, x, y);
 96
 97      // Now we assert the constraints to the solver.
 98      solver.assertFormula(constraint1);
 99      solver.assertFormula(constraint2);
100      solver.assertFormula(constraint3);
101      solver.assertFormula(constraint4);
102      //! [docs-java-quickstart-6 end]
103
104      // Check if the formula is satisfiable, that is,
105      // are there real values for x and y that satisfy all the constraints?
106      //! [docs-java-quickstart-7 start]
107      Result r1 = solver.checkSat();
108      //! [docs-java-quickstart-7 end]
109
110      // The result is either SAT, UNSAT, or UNKNOWN.
111      // In this case, it is SAT.
112      //! [docs-java-quickstart-8 start]
113      System.out.println("expected: sat");
114      System.out.println("result: " + r1);
115      //! [docs-java-quickstart-8 end]
116
117      // We can get the values for x and y that satisfy the constraints.
118      //! [docs-java-quickstart-9 start]
119      Term xVal = solver.getValue(x);
120      Term yVal = solver.getValue(y);
121      //! [docs-java-quickstart-9 end]
122
123      // It is also possible to get values for compound terms,
124      // even if those did not appear in the original formula.
125      //! [docs-java-quickstart-10 start]
126      Term xMinusY = tm.mkTerm(Kind.SUB, x, y);
127      Term xMinusYVal = solver.getValue(xMinusY);
128      //! [docs-java-quickstart-10 end]
129
130      // Further, we can convert the values to java types
131      //! [docs-java-quickstart-11 start]
132      Pair<BigInteger, BigInteger> xPair = xVal.getRealValue();
133      Pair<BigInteger, BigInteger> yPair = yVal.getRealValue();
134      Pair<BigInteger, BigInteger> xMinusYPair = xMinusYVal.getRealValue();
135
136      System.out.println("value for x: " + xPair.first + "/" + xPair.second);
137      System.out.println("value for y: " + yPair.first + "/" + yPair.second);
138      System.out.println("value for x - y: " + xMinusYPair.first + "/" + xMinusYPair.second);
139      //! [docs-java-quickstart-11 end]
140
141      // Another way to independently compute the value of x - y would be
142      // to perform the (rational) arithmetic manually.
143      // However, for more complex terms,
144      // it is easier to let the solver do the evaluation.
145      //! [docs-java-quickstart-12 start]
146      Pair<BigInteger, BigInteger> xMinusYComputed =
147          new Pair<>(xPair.first.multiply(yPair.second).subtract(xPair.second.multiply(yPair.first)),
148              xPair.second.multiply(yPair.second));
149      BigInteger g = xMinusYComputed.first.gcd(xMinusYComputed.second);
150      xMinusYComputed = new Pair<>(xMinusYComputed.first.divide(g), xMinusYComputed.second.divide(g));
151      if (xMinusYComputed.equals(xMinusYPair))
152      {
153        System.out.println("computed correctly");
154      }
155      else
156      {
157        System.out.println("computed incorrectly");
158      }
159      //! [docs-java-quickstart-12 end]
160
161      // Next, we will check satisfiability of the same formula,
162      // only this time over integer variables a and b.
163
164      // We start by resetting assertions added to the solver.
165      //! [docs-java-quickstart-13 start]
166      solver.resetAssertions();
167      //! [docs-java-quickstart-13 end]
168
169      // Next, we assert the same assertions above with integers.
170      // This time, we inline the construction of terms
171      // to the assertion command.
172      //! [docs-java-quickstart-14 start]
173      solver.assertFormula(tm.mkTerm(Kind.LT, tm.mkInteger(0), a));
174      solver.assertFormula(tm.mkTerm(Kind.LT, tm.mkInteger(0), b));
175      solver.assertFormula(
176          tm.mkTerm(Kind.LT, tm.mkTerm(Kind.ADD, a, b), tm.mkInteger(1)));
177      solver.assertFormula(tm.mkTerm(Kind.LEQ, a, b));
178      //! [docs-java-quickstart-14 end]
179
180      // We check whether the revised assertion is satisfiable.
181      //! [docs-java-quickstart-15 start]
182      Result r2 = solver.checkSat();
183
184      // This time the formula is unsatisfiable
185      System.out.println("expected: unsat");
186      System.out.println("result: " + r2);
187      //! [docs-java-quickstart-15 end]
188
189      // We can query the solver for an unsatisfiable core, i.e., a subset
190      // of the assertions that is already unsatisfiable.
191      //! [docs-java-quickstart-16 start]
192      List<Term> unsatCore = Arrays.asList(solver.getUnsatCore());
193      System.out.println("unsat core size: " + unsatCore.size());
194      System.out.println("unsat core: ");
195      for (Term t : unsatCore)
196      {
197        System.out.println(t);
198      }
199      //! [docs-java-quickstart-16 end]
200    }
201    Context.deletePointers();
202  }
203}