a time point ?tp1 preceeds a time point ?tp2.
(<=> (Tp< ?Tp1 ?Tp2) (Or (< (Time-Point.Year ?Tp1) (Time-Point.Year ?Tp2)) (And (= (Time-Point.Year ?Tp1) (Time-Point.Year ?Tp2)) (Or (< (Time-Point.Month ?Tp1) (Time-Point.Month ?Tp2)) (And (= (Time-Point.Month ?Tp1) (Time-Point.Month ?Tp2)) (Or (< (Time-Point.Day ?Tp1) (Time-Point.Day ?Tp2)) (And (= (Time-Point.Day ?Tp1) (Time-Point.Day ?Tp2)) (Or (< (Time-Point.Hour ?Tp1) (Time-Point.Hour ?Tp2)) (And (= (Time-Point.Hour ?Tp1) (Time-Point.Hour ?Tp2)) (Or (< (Time-Point.Minute ?Tp1) (Time-Point.Minute ?Tp2)) (And (= (Time-Point.Minute ?Tp1) (Time-Point.Minute ?Tp2)) (< (Time-Point.Second ?Tp1) (Time-Point.Second ?Tp2)))))))))))))
(<=> (Before ?Tr1 ?Tr2) (Tp< (Time-Range.End-Time ?Tr1) (Time-Range.Start-Time ?Tr2))) (<=> (After ?Tr1 ?Tr2) (Tp< (Time-Range.End-Time ?Tr2) (Time-Range.Start-Time ?Tr1))) (<=> (During ?Tr1 ?Tr2) (And (Tp> (Time-Range.Start-Time ?Tr1) (Time-Range.Start-Time ?Tr2)) (Tp< (Time-Range.End-Time ?Tr1) (Time-Range.End-Time ?Tr2)))) (<=> (Overlaps ?Tr1 ?Tr2) (And (Tp< (Time-Range.Start-Time ?Tr1) (Time-Range.Start-Time ?Tr2)) (Tp< (Time-Range.Start-Time ?Tr2) (Time-Range.End-Time ?Tr1)) (Tp< (Time-Range.End-Time ?Tr1) (Time-Range.End-Time ?Tr2)))) (<=> (Starts ?Tr1 ?Tr2) (And (Tp= (Time-Range.Start-Time ?Tr1) (Time-Range.Start-Time ?Tr2)) (Tp< (Time-Range.End-Time ?Tr1) (Time-Range.End-Time ?Tr2)))) (<=> (Tp< ?Tp1 ?Tp2) (Or (< (Time-Point.Year ?Tp1) (Time-Point.Year ?Tp2)) (And (= (Time-Point.Year ?Tp1) (Time-Point.Year ?Tp2)) (Or (< (Time-Point.Month ?Tp1) (Time-Point.Month ?Tp2)) (And (= (Time-Point.Month ?Tp1) (Time-Point.Month ?Tp2)) (Or (< (Time-Point.Day ?Tp1) (Time-Point.Day ?Tp2)) (And (= (Time-Point.Day ?Tp1) (Time-Point.Day ?Tp2)) (Or (< (Time-Point.Hour ?Tp1) (Time-Point.Hour ?Tp2)) (And (= (Time-Point.Hour ?Tp1) (Time-Point.Hour ?Tp2)) (Or (< (Time-Point.Minute ?Tp1) (Time-Point.Minute ?Tp2)) (And (= (Time-Point.Minute ?Tp1) (Time-Point.Minute ?Tp2)) (< (Time-Point.Second ?Tp1) (Time-Point.Second ?Tp2))))))))))))) (<=> (Tp> $Arg1 $Arg2) (Tp< $Arg2 $Arg1)) (Inverse Tp> Tp<)