(***************************************************************************)
(* Formalization of the Chou, Gao and Zhang's decision procedure.          *)
(* Julien Narboux (Julien@narboux.fr)                                      *)
(* LIX/INRIA FUTURS 2004-2006                                              *)
(* University of Strasbourg 2008                                           *)
(***************************************************************************)
Ltac local_uniformize_signed_areas := Runiformize_signed_areas.
(* Ltac local_uniformize_signed_areas := uniformize_signed_areas. *)
Ltac local_basic_simpl := Rbasic_simpl.
Ltac local_uniformize_signed_areas4 := uniformize_signed_areas4.
(* Tests uniformize in the goal *)
(* Test in the hypotheses *)
(* Hypotheses and goal tests *)

Lemma test13 : forall A B C :Point, S A B C + S C B A = 0 ->
S A B C + S B A C = 0 -> S A B C - S B C A = 0 .