+ denotes a time range ?time-range-2 whose length is longerthat ?time-range-1 by a duration ?duration.
A difference between two time points ?time-point-1 and ?time-point-2 is a
duration ?duration.
and also:
If $tau_1$, ..., $tau_n$ are numerical constants, then the term {tt (+ $tau_1 ... tau_n$)} denotes the sum $tau$ of the numbers
corresponding to those constants.
(=> (And (Duration ?Duration-1) (Duration ?Duration-2))
(=> (= (+ ?Duration-1 ?Duration-2) ?Duration-3)
(Duration ?Duration-3)))
(=> (+ ?Time-Range-1 ?Duration)
(=> (And (Time-Point ?Time-Range-1) (Duration ?Duration))
(=> (= (+ ?Time-Point-1 ?Duration) ?Time-Point-2)
(And (Time-Point ?Time-Point-1)
(Duration ?Duration)
(Time-Point ?Time-Point-2)))))
(=> (+ ?Time-Range-1 ?Duration)
(=> (And (Time-Range ?Time-Range-1) (Duration ?Duration))
(<=> (= (+ ?Time-Range-1 ?Duration) ?Time-Range-2)
(And (= (Start-Time-Of ?Time-Range-1)
(Start-Time-Of ?Time-Range-2))
(= (+ (End-Time-Of ?Time-Range-1) ?Duration)
(End-Time-Of ?Time-Range-2))))))
(Undefined (Arity +))
(=> (Time-Range ?Time-Range)
(Equals (+ (Start-Time-Of ?Time-Range) (Duration-Of ?Time-Range))
(End-Time-Of ?Time-Range)))