proposition: Lemma orsum_gle1 x x': gle (order_sum r g) x x' -> (glt r (Q x) (Q x') \/ (Q x = Q x' /\ gle (Vg g (Q x)) (P x) (P x'))).
proof: Proof. by move /orsum_gleP => [_ _]. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)