--- /dev/null
+/******************************************************************************
+ * Top contributors (to current version):
+ * Yoni Zohar
+ *
+ * This file is part of the cvc5 project.
+ *
+ * Copyright (c) 2009-2021 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 the api capabilities of cvc5.
+ *
+ */
+
+#include <cvc5/cvc5.h>
+
+#include <iostream>
+
+using namespace std;
+using namespace cvc5::api;
+
+int main()
+{
+ // Create a solver
+ Solver solver;
+
+ // We will ask the solver to produce models and unsat cores,
+ // hence these options should be turned on.
+ solver.setOption("produce-models", "true");
+ solver.setOption("produce-unsat-cores", "true");
+
+ // 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".
+
+ // Set the logic
+ solver.setLogic("ALL");
+
+ // In this example, we will define constraints over reals and integers.
+ // Hence, we first obtain the corresponding sorts.
+ Sort realSort = solver.getRealSort();
+ Sort intSort = solver.getIntegerSort();
+
+ // x and y will be real variables, while a and b will be integer variables.
+ // Formally, their cpp type is Term,
+ // and they are called "constants" in SMT jargon:
+ Term x = solver.mkConst(realSort, "x");
+ Term y = solver.mkConst(realSort, "y");
+ Term a = solver.mkConst(intSort, "a");
+ Term b = solver.mkConst(intSort, "b");
+
+ // Our constraints regarding x and y will be:
+ //
+ // (1) 0 < x
+ // (2) 0 < y
+ // (3) x + y < 1
+ // (4) x <= y
+ //
+
+ // 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 = solver.mkReal(0);
+ Term one = solver.mkReal(1);
+
+ // Next, we construct the term x + y
+ Term xPlusY = solver.mkTerm(PLUS, x, y);
+
+ // Now we can define the constraints.
+ // They use the operators +, <=, and <.
+ // In the API, these are denoted by PLUS, LEQ, and LT.
+ // A list of available operators is available in:
+ // src/api/cpp/cvc5_kind.h
+ Term constraint1 = solver.mkTerm(LT, zero, x);
+ Term constraint2 = solver.mkTerm(LT, zero, y);
+ Term constraint3 = solver.mkTerm(LT, xPlusY, one);
+ Term constraint4 = solver.mkTerm(LEQ, x, y);
+
+ // Now we assert the constraints to the solver.
+ solver.assertFormula(constraint1);
+ solver.assertFormula(constraint2);
+ solver.assertFormula(constraint3);
+ solver.assertFormula(constraint4);
+
+ // Check if the formula is satisfiable, that is,
+ // are there real values for x,y,z that satisfy all the constraints?
+ Result r1 = solver.checkSat();
+
+ // The result is either SAT, UNSAT, or UNKNOWN.
+ // In this case, it is SAT.
+ std::cout << "expected: sat" << std::endl;
+ std::cout << "result:" << r1 << std::endl;
+
+ // We can get 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 compound terms,
+ // even if those did not appear in the original formula.
+ Term xMinusY = solver.mkTerm(MINUS, x, y);
+ Term xMinusYVal = solver.getValue(xMinusY);
+
+ // We can now obtain thestring representations of the values.
+ std::string xStr = xVal.getRealValue();
+ std::string yStr = yVal.getRealValue();
+ std::string xMinusYStr = xMinusYVal.getRealValue();
+
+ std::cout << "value for x: " << xStr << std::endl;
+ std::cout << "value for y: " << yStr << std::endl;
+ std::cout << "value for x - y: " << xMinusYStr << std::endl;
+
+ // Further, we can convert the values to cpp types,
+ // using standard cpp conversion functions.
+ double xDouble = std::stod(xStr);
+ double yDouble = std::stod(yStr);
+ double xMinusYDouble = std::stod(xMinusYStr);
+
+ // Another way to independently compute the value of x and y would be using
+ // the ordinary cpp minus operator instead of asking the solver.
+ // However, for more complex terms,
+ // it is easier to let the solver do the evaluation.
+ double xMinusYComputed = xDouble - yDouble;
+ if (xMinusYComputed == xMinusYDouble)
+ {
+ std::cout << "computed correctly" << std::endl;
+ }
+ else
+ {
+ std::cout << "computed incorrectly" << std::endl;
+ }
+
+ // Next, we will check satisfiability of the same formula,
+ // only this time over integer variables a and b.
+
+ // We start by resetting assertions added to the solver.
+ solver.resetAssertions();
+
+ // Next, we assert the same assertions above with integers.
+ // This time, we inline the construction of terms
+ // to the assertion command.
+ solver.assertFormula(solver.mkTerm(LT, solver.mkInteger(0), a));
+ solver.assertFormula(solver.mkTerm(LT, solver.mkInteger(0), b));
+ solver.assertFormula(
+ solver.mkTerm(LT, solver.mkTerm(PLUS, a, b), solver.mkInteger(1)));
+ solver.assertFormula(solver.mkTerm(LEQ, a, b));
+
+ // We check whether the revised assertion is satisfiable.
+ Result r2 = solver.checkSat();
+
+ // This time the formula is unsatisfiable
+ std::cout << "expected: unsat" << std::endl;
+ std::cout << "result: " << r2 << std::endl;
+
+ // We can query the solver for an unsatisfiable core, i.e., a subset
+ // of the assertions that is already unsatisfiable.
+ std::vector<Term> unsatCore = solver.getUnsatCore();
+ std::cout << "unsat core size: " << unsatCore.size() << std::endl;
+ std::cout << "unsat core: " << std::endl;
+ for (const Term& t : unsatCore)
+ {
+ std::cout << t << std::endl;
+ }
+
+ return 0;
+}
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