A CycL sentence, represented in the Cyc Knowledge Base by #$CycLSentence
, is a type of CycL formula that constitutes a syntactically well-formed sentence in the CycL language. Every CycL sentence consists of a CycL expression denoting an instance of #$TruthFunction
(e.g. an instance of #$Predicate
or #$SententialRelation
) followed by one or more CycL terms, with the entire sequence enclosed in parentheses. For example, (isa Collection Thing)
and (genls ?FOO SpatialThing)
are both CycL sentences. Assertions are a notable type of CycL sentence.
![](https://www.cyc.com/wp-content/uploads/2019/11/Terms.png)
An Euler diagram of terms in Cyc.