End ABC.

(* Specifications: *)
Lemma equilateral_strict_conga_2 :
forall A B C,
equilateral_strict A B C ->
CongA B A C A B C.
Lemma equilateral_strict_conga_3 :
forall A B C,
equilateral_strict A B C ->
CongA C B A B C A.
Lemma conga3_equilateral :
forall A B C,
~ Col A B C ->
CongA B A C A B C ->
CongA A B C B C A ->
equilateral A B C.