The sentence {tt (member $tau_1$ $tau_2$)} is true if and only if the object denoted by $tau_1$ is contained in the set denoted by $tau_2$. As mentioned above, an object can be a member of another object if and only if the former is bounded and the latter is a set.Notes:
- Source: KIF Version 3.0 Specification
(=> (= (Generalized-Union ?Set-Of-Sets) ?Set)
(Forall (?S) (=> (Member ?S ?Set-Of-Sets) (Simple-Set ?S))))
(=> (= (Generalized-Intersection ?Set-Of-Sets) ?Set)
(Forall (?S) (=> (Member ?S ?Set-Of-Sets) (Simple-Set ?S))))
(=> (And (Set ?S1) (Set ?S2))
(<=> (Forall (?X) (<=> (Member ?X ?S1) (Member ?X ?S2)))
(= ?S1 ?S2)))
(=> (Subset ?S1 ?S2)
(Forall (?X) (=> (Member ?X ?S1) (Member ?X ?S2))))
(=> (And (Bounded ?U) (Forall (?X) (=> (Member ?X ?U) (Bounded ?X))))
(Bounded (Generalized-Union ?U)))
(<=> (Subset ?S1 ?S2)
(And (Set ?S1)
(Set ?S2)
(Forall (?X) (=> (Member ?X ?S1) (Member ?X ?S2)))))
(<=> (Instance-Of@Frame-Ontology ?Individual ?Class)
(Member (Listof ?Individual) ?Class))
(<=> (All-Instances@Frame-Ontology ?Class)
(And (Class@Frame-Ontology ?Class)
(Set ?Set-Of-Instances)
(Forall (?Instance)
(<=> (Member ?Instance ?Set-Of-Instances)
(Instance-Of@Frame-Ontology ?Instance ?Class)))))
(<=> (One-Of@Frame-Ontology @Members)
(Forall (?Instance)
(<=> (Instance-Of@Frame-Ontology ?Instance ?Class)
(Member ?Instance (Setof @Members)))))
(<=> (Subrelation-Of@Frame-Ontology ?Child-Relation ?Parent-Relation)
(And (Relation@Ol-User%Kif-Relations ?Child-Relation)
(Relation@Ol-User%Kif-Relations ?Parent-Relation)
(Forall (?Tuple)
(=> (Member ?Tuple ?Child-Relation)
(Member ?Tuple ?Parent-Relation)))))
(Forall (?S)
(=> (Not (Empty ?S))
(Exists (?U) (And (Member ?U ?S) (Disjoint ?U ?S)))))
(Exists (?S)
(And (Set ?S)
(Forall (?X)
(=> (Member ?X ?S)
(Double@Ol-User%Kif-Lists ?X)))
(Forall (?X ?Y ?Z)
(=> (And (Member (Listof ?X ?Y) ?S)
(Member (Listof ?X ?Z) ?S))
(= ?Y ?Z)))
(Forall (?U)
(=> (And (Bounded ?U) (Not (Empty ?U)))
(Exists (?V)
(And (Member ?V ?U)
(Member (Listof ?U ?V) ?S)))))))
(Exists (?U)
(And (Bounded ?U)
(Not (Empty ?U))
(Forall (?X)
(=> (Member ?X ?U)
(Exists (?Y)
(And (Member ?Y ?U)
(Proper-Subset ?X ?Y)))))))
(Forall (?Class)
(=> (Member ?Class ?Set-Of-Classes)
(Class@Frame-Ontology ?Class)))