Occurs at the same time as, together with, or jointly. This includes is co-incident with, is concurrent with, is contemporaneous with, and is concomitant with. Diagrammatically: =; if absolute time is not wanted in the definition, co-occur can be taken as a non-axiomatized primitive.
(=> (Co-Occur ?A ?B)
(Exists (?U)
(And (Exists (?C ?D ?E ?F)
(And (Beginpoint ?B ?F)
(Time-Value ?F ?E)
(Beginpoint ?A ?D)
(Time-Value ?D ?C)
(= ?C ?E)))
(Exists (?G ?H ?I ?J)
(And (Endpoint ?B ?J)
(Time-Value ?J ?I)
(Endpoint ?A ?H)
(Time-Value ?H ?G)
(= ?G ?I)))
(Exists (?K)
(And (The-Time-Unit ?A ?K) (Identity ?K ?U)))
(Exists (?L)
(And (The-Time-Unit ?B ?L) (Identity ?L ?U))))))