(***************************************************************************)
(* Formalization of the Chou, Gao and Zhang's decision procedure.          *)
(* Julien Narboux (Julien@narboux.fr)                                      *)
(* LIX/INRIA FUTURS 2004-2006                                              *)
(* University of Strasbourg 2008                                           *)
(***************************************************************************)
Require Export pythagoras_difference_lemmas.
Require Export ratios_elimination_lemmas.

Theorem elim_py_on_line_d_right :
forall (A B P Q Y : Point) (f : F),
on_line_d Y P Q f ->
Py A B Y = f * Py A B Q + (1 - f) * Py A B P.