(=> (Activity-Owner ?Actor) (Exists (?Activity-Ownership) (And (Activity-Ownership ?Activity-Ownership) (Owning-Actor ?Activity-Ownership ?Actor))))
(<=> (Activity-Owner ?Actor) (And (Actor ?Actor) (Exists (?Activity-Ownership) (And (Activity-Ownership ?Activity-Ownership) (Owning-Actor ?Activity-Ownership ?Actor)))))