(* Gabriel Braun February 2013 *)
Require Export GeoCoq.Tarski_dev.Annexes.quadrilaterals_inter_dec.
Section Vectors.
Context `{T2D:Tarski_2D}.
Context `{TE:@Tarski_euclidean Tn TnEQD}.

Lemma eqv_sym : forall A B C D, EqV A B C D -> EqV C D A B.