VB.NET 2005 Operator Overloading

Question

I'm having trouble finding a good example on using "IsTrue"/"IsFalse" as a user-defined overloaded operator in VB.NET 2005 (or even an example showing use of the un-overloaded "IsTrue" or "IsFalse"). Can anyone explain how an overloaded IsTrue/IsFalse would be declared and used?