(***************************************************************************)
(* Formalization of the Chou, Gao and Zhang's decision procedure.          *)
(* Julien Narboux (Julien@narboux.fr)                                      *)
(* LIX/INRIA FUTURS 2004-2006                                              *)
(* University of Strasbourg 2008                                           *)
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(** Area elimination *)
(** on_line *)
(** on_line_d *)
(* inter_ll *)

Lemma test_area_on_parallel_2  : forall I B C D X Y,
on_parallel I B C D -> S Y I X = S X Y B + B ** I / C ** D * S4 X C Y D.