public static void EqualsTests()
{
Func <Type, Type, bool> eq = (x, y) => x.Equals(y);
Func <Type, Eq <Type> > mk = t => Eq.Make(t, eq);
Assert.Equal(mk(typeof(string)), mk(typeof(string)));
Assert.Equal(mk(null), mk(null));
Assert.NotEqual(mk(typeof(int)), mk(typeof(string)));
Assert.NotEqual(mk(null), mk(typeof(string)));
Assert.NotEqual(mk(typeof(int)), mk(null));
}