From IAOA Wiki
- The Upper Cyc Ontology was in the 90's a set ofapproximately 3,000 terms capturing the most generalconcepts of human consensus reality as part of the Cyc project. As part of the project, different elements were developed: the Cyc representation language (CycL); the Cyc ontology; the Cyc knowledge base of general common-sense rules and assertions; and 4) the Cyc inference engine. (Source: Lenat, D.B., and Guha, R.V. (1989) Building Large Knowledge-Based Systems; Representation and Inference in the Cyc Project 1st edition, Addison-Wesley Longman Publishing Co., Inc. Boston, MA, USA)
- The aim was for Cyc to contain enough commonsense knowledge to support natural language understanding capabilities that enable it to read through and assimilate any encyclopedia article. It consisted of a foundation ontology and several domain-specific ontologies (called microtheories and later on collections). It was implemented using CyCL language.(Source: Lenat, D. and Guha R.V. (1990) CYC: A Midterm Report, AI Magazine, Vol. 11, No. 3).
- The current Cyc KB version contains more than 2.2 million assertions (facts and rules) describing more than 250,000 terms, including nearly 15,000 predicates. There is an open version, OpenCyc, as a freely available subset of the knowledge base that includes an ontology of 47,000 terms, which are defined and elaborated using 306,000 assertions. (Source: Matuszek, C., Cabral, J., Witbrock, M.J., and DeOliveira, J. (2006) An Introduction to the Syntax and Content of Cyc, AAAI Spring Symposium: Formalizing and Compiling Background Knowledge and Its Applications to Knowledge Representation and Question Answering, pp. 44-49.)