public void Comparisons()
{
IsTrue(F.Attr(Foo, zero).Equals(F.Attr(Foo, zero)));
IsFalse(F.Attr(Foo, zero).Equals(F.Attr(a, zero)));
IsFalse(zero.Equals(F.Attr(Foo, zero)));
IsTrue(F.Attr(Foo, a).Equals(F.Attr(Foo, a)));
IsFalse(F.Attr(Foo, a).Equals(F.Attr(Foo, b)));
IsFalse(a.Equals(F.Attr(Foo, a)));
}