The object-oriented approach was first applied to a deductive framework in O-logic (Object Logic) [Maier 1986], which was in turn based on the logic programming language LOGIN [Ait-Kachi and Nasr 1986].
Example 3.2 Consider the following rule in O-logic:
An extended O-logic based on O-logic was first proposed in Kifer and Wu , followed by a more general F-logic (Frame Logic) in Kifer and Lausen  and Kifer et al.
F-logic is a powerful deductive language with a well-defined semantics compared to O-logic. It supports functor objects and sets.
Unlike O-logic, which only supports simple attributes, F-logic supports parameterized attributes.