Logic programming immediately comes to mind. I've always had trouble to see the difference between imperative programming and procedural programming, and in a w

Logic programming immediately comes to mind. I've always had trouble to see the difference between imperative programming and procedural programming, and in a way OOP is procedural with lipstick (I'll wait that it is fashionable to bash FP to say the same about FP :-). Logic and declarative programming, on the other hand, are whole different beasts.