/// <summary>
/// Find x and y such that: x ^ y - 103 == x * y
/// </summary>
public static void BitvectorExample2()
{
print("BitvectorExample2");
using var svc = Z3Api.Create();
var bvSize = default(N32);
/* construct x ^ y - 103 == x * y */
var x = svc.BvConst("x", bvSize);
var y = svc.BvConst("y", bvSize);
var x_xor_y = svc.XOr(x, y);
var c103 = svc.BvNumeral("103", bvSize);
var lhs = svc.Sub(x_xor_y, c103);
var rhs = svc.Mul(x, y);
var ctr = svc.Eq(lhs, rhs);
print("find values of x and y, such that x ^ y - 103 == x * y");
/* find a model (i.e., values for x an y that satisfy the constraint */
Model m = Check(svc, ctr, Status.SATISFIABLE);
foreach (var e in m.Consts)
{
print($"{e.Key.Name}:{e.Key.ASTKind} = {e.Value}");
}
}
public static void BvExample1()
{
using var svc = Z3Api.Create();
var x = svc.BvVal(3);
var y = svc.BvVal(5);
var z = svc.Or(x, y);
var eval = z.Simplify();
inform($"{z.SExpr()} = {eval}:{eval.ASTKind}");
}
public static void EnumExamples()
{
using var svc = Z3Api.Create();
var choices = svc.Enum("Choices", "ChoiceA", "ChoiceB", "ChoiceC");
for (var i = 0u; i < choices.Consts.Length; i++)
{
inform($"Choice {i} = {choices.Const(i)}");
}
}
/// <summary>
/// Simple bit-vector example.
/// </summary>
/// <remarks>
/// This example disproves that x - 10 <= 0 IFF x <= 10 for (32-bit) machine integers
/// </remarks>
public static void BitvectorExample1()
{
var ctx = new Z3.Context();
using var svc = Z3Api.Own(ctx);
var bv_type = ctx.MkBitVecSort(32);
var x = (BitVecExpr)ctx.MkConst("x", bv_type);
var zero = (BitVecNum)ctx.MkNumeral("0", bv_type);
BitVecNum ten = ctx.MkBV(10, 32);
BitVecExpr x_minus_ten = ctx.MkBVSub(x, ten);
/* bvsle is signed less than or equal to */
BoolExpr c1 = ctx.MkBVSLE(x, ten);
BoolExpr c2 = ctx.MkBVSLE(x_minus_ten, zero);
BoolExpr thm = ctx.MkIff(c1, c2);
print("disprove: x - 10 <= 0 IFF x <= 10 for (32-bit) machine integers");
Disprove(ctx, thm);
}
