theorem
  for P being compact non empty Subset of TOP-REAL 2 st P is
  being_simple_closed_curve holds W-min(P)<>E-max(P)
proof
  let P be compact non empty Subset of TOP-REAL 2;
  assume
A1: P is being_simple_closed_curve;
  now
A2: |[W-bound P, lower_bound (proj2|W-most P)]|=W-min(P) &
|[E-bound P, upper_bound (proj2
    | E-most P)]|=E-max(P) by PSCOMP_1:def 19,def 23;
    assume W-min(P)=E-max(P);
    then W-bound P= E-bound P by A2,SPPOL_2:1;
    hence contradiction by A1,Th17;
  end;
  hence thesis;
end;
