11. Rule-based systems were the predominate knowledge representation mechanism for virtually all early expert systems. 12. Examples of knowledge representation formalisms include theorem provers, and classifiers. 13. Knowledge representation and knowledge engineering are central to AI research.14. Past publications have addressed questions in computational reflection, meta-level architecture, programming languages, and knowledge representation . 15. Reification is one of the most frequently used techniques of conceptual analysis and knowledge representation . 16. "' Reification "'in knowledge representation is the process of turning a predicate into an object. 17. DL was first introduced into Knowledge Representation ( KR ) systems to overcome this deficiency. 18. Frames were originally derived from semantic networks and are therefore part of structure based knowledge representations . 19. MultiNet is claimed to be one of the most comprehensive and thoroughly described knowledge representation systems. 20. Knowledge Representation languages have also lacked easy readability.
