let C be non empty compact non horizontal non vertical Subset of (TOP-REAL 2); for n being Nat holds L~ (Cage (C,n)) = (L~ (Upper_Seq (C,n))) \/ (L~ (Lower_Seq (C,n)))
let n be Nat; L~ (Cage (C,n)) = (L~ (Upper_Seq (C,n))) \/ (L~ (Lower_Seq (C,n)))
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;
then
L~ (Rotate ((Cage (C,n)),(W-min (L~ (Cage (C,n)))))) = (L~ (Upper_Seq (C,n))) \/ (L~ (Lower_Seq (C,n)))
by SPPOL_2:24;
hence
L~ (Cage (C,n)) = (L~ (Upper_Seq (C,n))) \/ (L~ (Lower_Seq (C,n)))
by REVROT_1:33; verum