unit test of predicate logic :-)

PredicateLogicTests.cs

[TestFixture]
public class PredicateLogicTests
{
    [Test]
    public void TestNegationOfUniversalQuantifier()
    {
        var empty = new int[0];
        var allOdd = new[] { 1, 3, 5 };
        var allEven = new[] { 2, 4, 6 };
        var allNumbers = new[] { 1, 2, 3 };

        Func<int, bool> isEven = x => (x % 2) == 0;

        Assert.IsFalse(AllTest(allOdd, isEven));
        Assert.IsFalse(AnyTest(allOdd, isEven));
        Assert.IsTrue(AllTest(allEven, isEven));
        Assert.IsTrue(AnyTest(allEven, isEven));
        Assert.IsFalse(AllTest(allNumbers, isEven));
        Assert.IsFalse(AnyTest(allNumbers, isEven));
        Assert.IsTrue(AllTest(empty, isEven));
        Assert.IsTrue(AnyTest(empty, isEven));
    }

    private static bool AllTest(IEnumerable<int> data, Func<int, bool> predicate)
    {
        return data.All(predicate);
    }

    private static bool AnyTest(IEnumerable<int> data, Func<int, bool> predicate)
    {
        return !data.Any(x => !predicate(x));
    }
}