Microsoft.Z3.Context.MkBVSub C# (CSharp) Méthode

MkBVSub() public méthode

Two's complement subtraction.
The arguments must have the same bit-vector sort.
public MkBVSub ( BitVecExpr t1, BitVecExpr t2 ) : BitVecExpr
t1 BitVecExpr
t2 BitVecExpr
Résultat BitVecExpr
        public BitVecExpr MkBVSub(BitVecExpr t1, BitVecExpr t2)
        {
            Contract.Requires(t1 != null);
            Contract.Requires(t2 != null);
            Contract.Ensures(Contract.Result<BitVecExpr>() != null);

            CheckContextMatch(t1);
            CheckContextMatch(t2);
            return new BitVecExpr(this, Native.Z3_mk_bvsub(nCtx, t1.NativeObject, t2.NativeObject));
        }

Usage Example

Exemple #1
0
    public void Run()
    {
        Dictionary<string, string> cfg = new Dictionary<string, string>() {
            { "AUTO_CONFIG", "true" } };

        using (Context ctx = new Context(cfg))
        {
            BitVecExpr x = ctx.MkBVConst("x", 32);
            BitVecExpr[] powers = new BitVecExpr[32];
            for (uint i = 0; i < 32; i++)
                powers[i] = ctx.MkBVSHL(ctx.MkBV(1, 32), ctx.MkBV(i, 32));

            BoolExpr step_zero = ctx.MkEq(ctx.MkBVAND(x, ctx.MkBVSub(x, ctx.MkBV(1, 32))), ctx.MkBV(0, 32));

            BoolExpr fast = ctx.MkAnd(ctx.MkNot(ctx.MkEq(x, ctx.MkBV(0, 32))),
                                      step_zero);

            BoolExpr slow = ctx.MkFalse();
            foreach (BitVecExpr p in powers)
                slow = ctx.MkOr(slow, ctx.MkEq(x, p));

        TestDriver.CheckString(fast, "(and (not (= x #x00000000)) (= (bvand x (bvsub x #x00000001)) #x00000000))");

            Solver s = ctx.MkSolver();
            s.Assert(ctx.MkNot(ctx.MkEq(fast, slow)));
            TestDriver.CheckUNSAT(s.Check());

            s = ctx.MkSolver();
            s.Assert(ctx.MkNot(step_zero));
            TestDriver.CheckSAT(s.Check());
        }
    }
All Usage Examples Of Microsoft.Z3.Context::MkBVSub
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