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))))