ar in the arg0 position of a #$CycLSentence; and a sentence (if quantificationally closed; see #$CycLClosedSentence), will generally be either true or false (with respect to a given context or interpretation). The major subcollections of #$TruthFunction are #$Predicate, #$LogicalConnective, and #$Quantifier (qq.v.). Another important subcollection of #$Relation is #$Function-Denotational (q.v.), whose instances are functions the CycL expressions for which can appear in the arg0 position of a #$CycLNonAtomic