Examples with Expr com.google.api.expr.v1alpha1.Expr used on opensource projects

Example 36 with Expr

use of com.google.api.expr.v1alpha1.Expr in project java-smt by sosy-lab.

the class CVC4NativeAPITest method checkSimpleEqualityUnsat.

@Test
public void checkSimpleEqualityUnsat() {
    Expr zero = exprMgr.mkConst(new Rational(0));
    Expr one = exprMgr.mkConst(new Rational(1));
    Expr assertion = exprMgr.mkExpr(Kind.EQUAL, zero, one);
    smtEngine.assertFormula(assertion);
    Result satCheck = smtEngine.checkSat();
    assertThat(satCheck.isSat()).isEqualTo(Sat.UNSAT);
}

Example 37 with Expr

use of com.google.api.expr.v1alpha1.Expr in project java-smt by sosy-lab.

the class CVC4NativeAPITest method checkSimpleFPSat.

/**
 * Do not ever try to use decimals in a new Rational that has only a 0 as decimal. This will
 * SIGSEV CVC4!
 */
@Test
public void checkSimpleFPSat() {
    // x * y = 1/4
    RoundingMode rm = RoundingMode.roundNearestTiesToAway;
    Expr rmExpr = exprMgr.mkConst(rm);
    Expr oneFourth = exprMgr.mkConst(new FloatingPoint(new FloatingPointSize(8, 24), rm, new Rational(1, 4)));
    Expr varX = exprMgr.mkVar("x", exprMgr.mkFloatingPointType(8, 24));
    Expr varY = exprMgr.mkVar("y", exprMgr.mkFloatingPointType(8, 24));
    Expr assertion1 = exprMgr.mkExpr(Kind.FLOATINGPOINT_EQ, exprMgr.mkExpr(Kind.FLOATINGPOINT_MULT, rmExpr, varX, varY), oneFourth);
    smtEngine.assertFormula(assertion1);
    Result satCheck = smtEngine.checkSat();
    assertThat(satCheck.isSat()).isEqualTo(Sat.SAT);
}

Example 38 with Expr

use of com.google.api.expr.v1alpha1.Expr in project java-smt by sosy-lab.

the class CVC4NativeAPITest method checkQuantifierEliminationBV.

/**
 * CVC4 does not support Bv quantifier elim. This is expected to fail!
 */
@Test
public void checkQuantifierEliminationBV() {
    // build formula: exists y : bv[2]. x * y = 1
    // quantifier-free equivalent: x = 1 | x = 3
    // or extract_0_0 x = 1
    int width = 2;
    Expr xBv = exprMgr.mkVar("x_bv", exprMgr.mkBitVectorType(width));
    Expr yBv = exprMgr.mkVar("y_bv", exprMgr.mkBitVectorType(width));
    Expr body = exprMgr.mkExpr(Kind.EQUAL, exprMgr.mkExpr(Kind.MULT, xBv, yBv), exprMgr.mkConst(new BitVector(1)));
    Expr xBound = exprMgr.mkBoundVar("y_bv", exprMgr.mkBitVectorType(width));
    vectorExpr vec = new vectorExpr();
    vec.add(xBound);
    Expr quantifiedVars = exprMgr.mkExpr(Kind.BOUND_VAR_LIST, vec);
    Expr bodySubst = body.substitute(yBv, xBound);
    Expr assertion = exprMgr.mkExpr(Kind.EXISTS, quantifiedVars, bodySubst);
    assertThrows(RuntimeException.class, () -> smtEngine.doQuantifierElimination(assertion, true));
}

Example 39 with Expr

use of com.google.api.expr.v1alpha1.Expr in project java-smt by sosy-lab.

the class CVC4NativeAPITest method checkUnsatCore.

@Test
public void checkUnsatCore() {
    // (a & b) & (not(a OR b))
    // Enable UNSAT Core first!
    smtEngine.setOption("produce-unsat-cores", new SExpr(true));
    Type boolType = exprMgr.booleanType();
    Expr a = exprMgr.mkVar("a", boolType);
    Expr b = exprMgr.mkVar("b", boolType);
    Expr aAndb = exprMgr.mkExpr(Kind.AND, a, b);
    Expr notaOrb = exprMgr.mkExpr(Kind.NOT, exprMgr.mkExpr(Kind.OR, a, b));
    smtEngine.assertFormula(aAndb);
    smtEngine.assertFormula(notaOrb);
    Result satCheck = smtEngine.checkSat();
    assertThat(satCheck.isSat()).isEqualTo(Sat.UNSAT);
    UnsatCore unsatCore = smtEngine.getUnsatCore();
    // UnsatCores are iterable
    for (Expr e : unsatCore) {
        assertThat(e.toString()).isIn(Arrays.asList("(not (or a b))", "(and a b)"));
    }
}

Example 40 with Expr

use of com.google.api.expr.v1alpha1.Expr in project java-smt by sosy-lab.

the class CVC4NumeralFormulaManager method consistsOfNumerals.

/**
 * Check whether the current term is numeric and the value of a term is determined by only
 * numerals, i.e. no variable is contained. This method should check as precisely as possible the
 * situations in which CVC4 supports arithmetic operations like multiplications.
 *
 * <p>Example: TRUE for "1", "2+3", "ite(x,2,3) and FALSE for "x", "x+2", "ite(1=2,x,0)"
 */
boolean consistsOfNumerals(Expr val) {
    Set<Expr> finished = new HashSet<>();
    Deque<Expr> waitlist = new ArrayDeque<>();
    waitlist.add(val);
    while (!waitlist.isEmpty()) {
        Expr e = waitlist.pop();
        if (!finished.add(e)) {
            continue;
        }
        if (isNumeral(e)) {
        // true, skip and check others
        } else if (NUMERIC_FUNCTIONS.contains(e.getKind())) {
            Iterables.addAll(waitlist, e);
        } else if (ITE.equals(e.getKind())) {
            // ignore condition, just use the if- and then-case
            waitlist.add(e.getChild(1));
            waitlist.add(e.getChild(2));
        } else {
            return false;
        }
    }
    return true;
}