public void TestFreeVariables()
{
SortedSet <string> variables;
LogicExpression test = new NumExists("n", n == m);
FreeVariableLister lister = new FreeVariableLister();
variables = test.Accept(lister);
Assert.AreEqual(1, variables.Count);
Assert.IsTrue(variables.Contains("m"));
test = new NumExists("x", n == n);
lister = new FreeVariableLister();
variables = test.Accept(lister);
Assert.AreEqual(1, variables.Count);
Assert.IsTrue(variables.Contains("n"));
test = (new NumThe("n", n == two)) == two;
lister = new FreeVariableLister();
variables = test.Accept(lister);
Assert.AreEqual(0, variables.Count);
//Assert.IsTrue(lister.Variables.Contains("n"));
// this test shows that the original method does not work
test = n == n & new NumExists("n", n == two);
lister = new FreeVariableLister();
variables = test.Accept(lister);
Assert.AreEqual(1, variables.Count);
}
public void TestSubstitution()
{
var subst = new VariableSubstituter("n", two);
var result = n.Accept(subst);
Assert.AreEqual("2", testAsync(result, 200).Result);
result = zero.Accept(subst);
Assert.AreEqual("0", testAsync(result, 200).Result);
var exists = new NumExists("n", n == n);
result = exists.Accept(subst);
Assert.AreEqual(True, testAsync(result, 200).Result);
var test = new Apply(new LambdaExpression("n", n == n), two);
Assert.AreEqual(True, testAsync(test, 200).Result);
// test that substitution avoids explosions
var test2 = new Apply(new LambdaExpression("x", logicTrue), logicLoop);
Assert.AreEqual(True, testAsync(test2, 200).Result);
var test3 = new Apply(new LambdaExpression("x", logicLoop), logicTrue);
Assert.AreEqual(Loop, testAsync(test3, 500).Result);
var test4 = new Apply(new LambdaExpression("x", x & logicTrue), logicLoop);
Assert.AreEqual(Loop, testAsync(test4, 500).Result);
var test5 = new Apply(new LambdaExpression("x", x | logicTrue), logicLoop);
Assert.AreEqual(True, testAsync(test5, 500).Result);
}
public T Visit(NumExists expression)
{
expression.Accept(this);
return(default(T));
}