a time range ?tr1 preceeds a time ranage ?tr2.
(<=> (Before ?Tr1 ?Tr2) (Tp< (Time-Range.End-Time ?Tr1) (Time-Range.Start-Time ?Tr2)))
(<=> (Before ?Tr1 ?Tr2) (Tp< (Time-Range.End-Time ?Tr1) (Time-Range.Start-Time ?Tr2))) (<=> (After $Arg1 $Arg2) (Before $Arg2 $Arg1)) (Inverse After Before) (<=> (Before= ?Tr1 ?Tr2) (Or (Before ?Tr1 ?Tr2) (Meets ?Tr1 ?Tr2))) (<=> (Disjoint-Tr ?Tr1 ?Tr2) (Or (Before ?Tr1 ?Tr2) (Before ?Tr2 ?Tr1)))