Require Export GeoCoq.Tarski_dev.Ch14_sum.
Section T14_prod.
Context `{T2D:Tarski_2D}.
Context `{TE:@Tarski_euclidean Tn TnEQD}.

(* Specifications: *)
Lemma prod_to_prodp : forall O E E' A B C, Prod O E E' A B C -> Prodp O E E' A B C.
Lemma project_pj : forall P P' A B X Y, Proj P P' A B X Y -> Pj X Y P P'.
Lemma prodp_to_prod : forall O E E' A B C, Prodp O E E' A B C -> Prod O E E' A B C.
Section Grid.