(** This is SSS congruence. *)

Lemma l11_51 : forall A B C A' B' C',
A <> B -> A <> C -> B <> C -> Cong A B A' B' -> Cong A C A' C' -> Cong B C B' C' ->
CongA B A C B' A' C' /\ CongA A B C A' B' C' /\ CongA B C A B' C' A'.