Existentially Quantified Sentences
(exists <individual variable> <sentence>)
E.g, (forall ?b1 (or (on ?b1 table) (exists ?b2 (On ?b1 ?b2))))
- TIV((exists ?var sent)) =
- true when TIV’(sent) = true
for some version V’ of V with respect to variable ?var
- false otherwise
(exists (<individual variable>*) <sentence>)
E.g., (exists (?b1 ?b2) (and (On ?b1 ?A) (Above ?A ?b2)))
- TIV ((exists (?var1 … ?varn) sent)) =
- true when TIV’(sent) = true
for some version V’ of V with respect to ?var1 … ?varn
- false otherwise
forall not in the scope of an exists may be omitted
E.g, (or (on ?b1 table) (exists ?b2 (On ?b1 ?b2)))