types of logical or/and operations. My position is more like: if the operation doesn't return a bool, it shouldn't even be in the realm of consideration for overloading operator|| or operator&&.
does return bool .. when (lazy) evaluation is triggered.
It's sort of like building a program with nothing but one class called "object".
Relations in LP loosely correspond to functions in the imperative paradigm and not objects.
It seems like you would be better off having a well defined container class that holds fact objects, for example.
I encourage you to pursue the list<facts> approach to see the pitfalls. But before you implement LP ... understand LP. Solve a few problems using any LP system, Castor or whatever. Your concerns are natural for an OO expert (and beginner in LP) who is wondering why it is this the way it is. -Roshan