proposition: Lemma lemma_equalanglesreflexive : forall A B C, nCol A B C -> CongA A B C A B C.
proof: Proof. intros. assert (CongA A B C C B A) by (conclude lemma_ABCequalsCBA). assert (nCol C B A) by (conclude lemma_equalanglesNC). assert (CongA C B A A B C) by (conclude lemma_ABCequalsCBA). assert (CongA A B C A B C) by (conclude lemma_equalanglestransitive). close. Qed.
imports: GeoCoq.Elements.OriginalProofs.lemma_ABCequalsCBA GeoCoq.Elements.OriginalProofs.lemma_equalanglestransitive