Section Projections.
Context `{T2D:Tarski_2D}.
Context `{TE:@Tarski_euclidean Tn TnEQD}.
intros.
unfold Proj in H0.
spliter.
induction H4; tauto.
Qed.
intros.
unfold Proj in *.
spliter.
repeat split; Col.
Qed.

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