Require Export GeoCoq.Tarski_dev.Ch14_prod.
Section Order.
Context `{T2D:Tarski_2D}.
Context `{TE:@Tarski_euclidean Tn TnEQD}.

Lemma sum_pos_pos : forall O E E' A B AB,
Ps O E A -> Ps O E B -> Sum O E E' A B AB -> Ps O E AB.