CycL First-Order Logic Language

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A CycL First-Order Logic Language is a knowledge representation language used in Cyc Projects.




  • (Cycorp, 2017) ⇒ "CycL: The Cyc Knowledge Representation Language" Retrieved:2017-6-11.
    • CycL is Cyc’s large and extraordinarily flexible knowledge representation language. It is essentially an augmentation of first-order predicate calculus (FOPC), with extensions to handle equality, default reasoning, skolemization, and some second-order features. (For example, quantification over predicates is allowed in some circumstances, and complete assertions can appear as intensional components of other assertions.) CycL uses a form of circumscription, includes the unique names assumption, and can make use of the closed world assumption where appropriate.


  • (Cycorp, 2017) ⇒ "Cycl Syntax" Retrieved:2017-6-11.
    • CycL is a formal language whose syntax derives from first-order predicate calculus (the language of formal logic) and from Lisp. In order to express common sense knowledge, however, it goes far beyond first order logic. The vocabulary of CycL consists of terms. The set of terms can be divided into constants, non-atomic terms (NATs), variables, and a few other types of objects. Terms are combined into meaningful CycL expressions, which are used to make assertions in the Cyc knowledge base. (...)