fact: Definition TCong A B C D := Cong A B C D \/ (A=B /\ C=D).
imports: GeoCoq.Axioms.tarski_axioms GeoCoq.Elements.OriginalProofs.proposition_01 GeoCoq.Elements.OriginalProofs.lemma_congruenceflip GeoCoq.Elements.OriginalProofs.lemma_extension Classical