(<=> (Activity-Owner ?Actor)
(And (Actor ?Actor)
(Exists (?Activity-Ownership)
(And (Activity-Ownership ?Activity-Ownership)
(Owning-Actor ?Activity-Ownership ?Actor)))))
(<=> (Actual-Doer ?X)
(And (Actor ?X)
(Exists (?Activity) (Actually-Execute ?X ?Activity))))
(<=> (Customer ?X)
(And (Legal-Entity ?X)
(Actor ?X)
(Or (Exists (?Sale) (Actual-Customer ?Sale ?X))
(Exists (?Potential-Sale)
(Potential-Customer ?Potential-Sale ?X))
(Exists (?Sale-Offer)
(Specified-Potential-Customer ?Sale-Offer ?X)))))
(<=> (Owner ?Owner)
(And (Actor ?Owner)
(Exists (?Ownership) (Owning-Actor ?Ownership ?Owner))))
(<=> (Partner ?Partner)
(And (Person ?Partner)
(Actor ?Partner)
(Exists (?Partnership) (Partner-Of ?Partner ?Partnership))))