proposition: Lemma g2_10 : forall A B C, BetG A B A -> BetG C B A.
proof: Proof. intros A B C HBet; do 2 apply g2_9; auto. Qed.
imports: GeoCoq.Axioms.tarski_axioms GeoCoq.Axioms.gupta_inspired_variant_axioms GeoCoq.Tarski_dev.Ch05_bet_le