Library zayin_conjugate

Require Import PointsETC.

Open Scope R_scope.

Section Triangle.

Context `{M:triangle_theory}.

Definition zayin_conjugate P U :=
 match P,U with
  cTriple p q r, cTriple u v w
   let h p q r x y z := p×(y + z)^2 - r×y^2 - q×z^2 + (p - r)*x×y + (p - q)*x×z in
  cTriple (h p q r u v w) (h q r p v w u) (h r p q w u v)
 end.

Lemma X2_is_zayin_conjugate_of_X1_X6 :
 eq_points X_2 (zayin_conjugate X_1 X_6).
Proof.
intros.
red;simpl; repeat split; field; repeat split;try assumption.
Qed.

End Triangle.