A predicate category and a specialization of intensional representation predicate (q.v.). First-order collection predicates are used to make statements about first-order collections or types, primarily in order to say something about their instances. They generally provide a simpler way of stating what could be stated (albeit less tersely) without the use of collection-predicates (viz. by referring more directly to the instances themselves). More precisely: each instance of type predicate is a predicate at least one of whose relata is always a first-order Cyc collection (q.v.). Such predicates are typically used to make ground-atomic sentences (see CycL closed atomic sentence) that are in principle equivalent to certain quantified sentences that involve no set-or-collection-predicates.

For example, arg isa for type is a type-level correlate of Arg Isa that enables one to place a particular argument-type constraint on every instance of a type of relationship in one fell-swoop. Thus, a ground-atomic sentence (arg isa for type RELNTYPE ARGNUM COL) is equivalent to the quantified sentence

  (For All ?RELN
    (Implies
      (Isa ?RELN RELNTYPE)
      (Arg Isa ?RELN ARGNUM COL))) .