An individual or individuals classified according to their age.
(=> (Age-Group ?Self) (Exists (?A) (And (Mereological-Member ?Self ?A) (Physical-Person ?A) (Exists (?B) (And (Age ?A ?B) (Age-Value-Filler ?B))) (Forall (?B ?C) (=> (And (Age ?A ?B) (Age ?A ?C)) (= ?B ?C))))))