reserve n for Nat;

theorem
  for C be compact non vertical non horizontal Subset of TOP-REAL 2
  holds Upper_Seq(C,n) is_in_the_area_of Cage(C,n)
proof
  let C be compact non vertical non horizontal Subset of TOP-REAL 2;
  E-max L~Cage(C,n) in rng Cage(C,n) by SPRECT_2:46;
  then E-max L~Cage(C,n) in rng Rotate(Cage(C,n),W-min L~Cage(C,n)) by
FINSEQ_6:90,SPRECT_2:43;
  hence thesis by Th1,JORDAN1B:10;
end;
