Editing Knowledge-based systems (section)

==Components==
The knowledge base contains domain-specific facts and rules<ref>{{Cite web |last=Smith |first=Reid |date=May 8, 1985 |title=Knowledge-Based Systems Concepts, Techniques, Examples |url=http://www.reidgsmith.com/Knowledge-Based_Systems_-_Concepts_Techniques_Examples_08-May-1985.pdf |access-date=9 November 2013 |website=reidgsmith.com |publisher=Schlumberger-Doll Research}}</ref>  about a problem domain (rather than knowledge implicitly embedded in procedural code, as in a conventional computer program). In addition, the knowledge may be structured by means of a [[Subsumption relation|subsumption]] [[Ontology (information science)|ontology]], [[Frame (artificial intelligence)|frames]], [[conceptual graph]], or logical assertions.<ref>{{Cite book |last=Sowa |first=John F. |url=https://archive.org/details/knowledgereprese00sowa_0 |title=Knowledge Representation: Logical, Philosophical, and Computational Foundations |date=2000 |publisher=Brooks / Cole |isbn=978-0-534-94965-5 |edition=1st |location=Pacific Grove}}</ref>

The inference engine uses general-purpose reasoning methods to infer new knowledge and to solve problems in the problem domain. Most commonly, it employs [[forward chaining]] or [[backward chaining]]. Other approaches include the use of [[automated theorem proving]], [[logic programming]], [[blackboard system]]s, and [[Rewriting|term rewriting systems]] such as [[Constraint Handling Rules]] (CHR). These more formal approaches are covered in detail in the Wikipedia article on [[knowledge representation and reasoning]].