F-logic (Frame logic) is a knowledge representation and ontology language. It combines the advantages of conceptual modeling with object-oriented, frame-based languages, and offers a declarative, compact and simple syntax, and the well-defined semantics of a logic programming language.
Features include, among others, object identity, complex objects, inheritance, polymorphism, query methods, encapsulation. F-logic stands in the same relationship to object-oriented programming as classical relational calculus stands to relational database programming.