a time point ?tp1 is equal to a time point ?tp2.
(<=> (Tp= ?Tp1 ?Tp2) (And (= (Time-Point.Year ?Tp1) (Time-Point.Year ?Tp2)) (= (Time-Point.Month ?Tp1) (Time-Point.Month ?Tp2)) (= (Time-Point.Day ?Tp1) (Time-Point.Day ?Tp2)) (= (Time-Point.Hour ?Tp1) (Time-Point.Hour ?Tp2)) (= (Time-Point.Minute ?Tp1) (Time-Point.Minute ?Tp2)) (= (Time-Point.Second ?Tp1) (Time-Point.Second ?Tp2))))