UNIT-TIME-RANGE-CLASS deontes a time ragne whose duration is a unit length.
(<=> (Unit-Time-Range-Class ?Class)
(And (Discrete-Time-Range-Class ?Class)
(Forall (?I)
(=> (Instance-Of ?I ?Class)
(= (Time-Range.Duration ?I)
(Time-Range-Unit ?Class))))))
(Forall (?I)
(=> (Instance-Of ?I ?Class)
(= (Time-Range.Duration ?I) (Time-Range-Unit ?Class))))
(Discrete-Time-Range-Class ?Class)
(<=> (Unit-Time-Range-Class ?Class)
(And (Discrete-Time-Range-Class ?Class)
(Forall (?I)
(=> (Instance-Of ?I ?Class)
(= (Time-Range.Duration ?I)
(Time-Range-Unit ?Class))))))