theorem :: SYSREL:40

for R, S being Relation holds
( ( S * R = S & R * (R \ (id (dom R))) = {} & R * S = R & S * (S \ (id (dom S))) = {} implies CL S = CL R ) & ( R * S = S & (R \ (id (dom R))) * R = {} & S * R = R & (S \ (id (dom S))) * S = {} implies CL S = CL R ) ) by Th39;