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 = new Pair<>(
147          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 =
151          new Pair<>(xMinusYComputed.first.divide(g), xMinusYComputed.second.divide(g));
152      if (xMinusYComputed.equals(xMinusYPair))
153      {
154        System.out.println("computed correctly");
155      }
156      else
157      {
158        System.out.println("computed incorrectly");
159      }
160      //! [docs-java-quickstart-12 end]
161
162      // Next, we will check satisfiability of the same formula,
163      // only this time over integer variables a and b.
164
165      // We start by resetting assertions added to the solver.
166      //! [docs-java-quickstart-13 start]
167      solver.resetAssertions();
168      //! [docs-java-quickstart-13 end]
169
170      // Next, we assert the same assertions above with integers.
171      // This time, we inline the construction of terms
172      // to the assertion command.
173      //! [docs-java-quickstart-14 start]
174      solver.assertFormula(tm.mkTerm(Kind.LT, tm.mkInteger(0), a));
175      solver.assertFormula(tm.mkTerm(Kind.LT, tm.mkInteger(0), b));
176      solver.assertFormula(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}