theorem Th22:
  for X being Subset of TOP-REAL 2, p being Point of TOP-REAL 2 st
  p in X holds (proj1|X).p = p`1
proof
  let X be Subset of TOP-REAL 2, p be Point of TOP-REAL 2;
  assume p in X;
  hence (proj1|X).p = proj1.p by FUNCT_1:49
    .= p`1 by Def5;
end;
