Require Export GeoCoq.Tarski_dev.Ch16_coordinates.
Section PythagoreanFun.
Context `{T2D:Tarski_2D}.
Context `{TE:@Tarski_euclidean Tn TnEQD}.

(* Specifications: *)
Lemma Ps_Col : forall O E A, Ps O E A -> Col O E A.
Lemma PythRel_exists : forall O E E', ~ Col O E  E' -> forall A B,
Col O E A -> Col O E B ->
exists C, PythRel O E E' A B C.
Lemma opp_same_square : forall O E E' A B A2, Opp O E E' A B -> Prod O E E' A A A2 -> Prod O E E' B B A2.
intros.