
theorem c1:
for R being preordered Ring,
    P being Preordering of R,
    a being Element of R holds a <=P, a
proof
let R be preordered Ring, P be Preordering of R;
let a be Element of R;
a <=_(OrdRel P), a by REALALG1:1;
hence thesis by lemOP;
end;
