(** This is SSS congruence. *)

(* Specifications: *)
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'.
Lemma conga_distinct : forall A B C D E F, CongA A B C D E F -> CongA A B C D E F /\ A <> B /\ C <> B /\ D <> E /\ F <> E.
(** This is SSA congruence with a restriction *)
Lemma l11_52 : forall A B C A' B' C',
CongA A B C A' B' C' -> Cong A C A' C' -> Cong B C B' C' -> Le B C A C ->
Cong B A B' A' /\ CongA B A C B' A' C' /\ CongA B C A B' C' A'.
Lemma l11_53 : forall A B C D,
Per D C B -> C <> D -> A <> B -> B <> C -> Bet A B C ->
LtA C A D C B D /\ Lt B D A D.