A relationship between an Actor and an Activity whereby the Actor has performed the Activity.
(=> (Planning-Assumption ?Planning ?Assumption)
(Exists (?Doer)
(And (Actor ?Doer)
(Actually-Execute ?Doer ?Planning)
(Assumed ?Doer ?Assumption))))
(<=> (Actual-Doer ?X)
(And (Actor ?X)
(Exists (?Activity) (Actually-Execute ?X ?Activity))))