a time range ?tr1 and a time range ?tr2 overlaps.
(<=> (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))))