proposition: Lemma proper_6 : forall p, Proper ((fun t1 t2 : SetOfPairsOfPositiveOrderedType.t => Pos.eq (fstpp t1) (fstpp t2) /\ Pos.eq (sndpp t1) (sndpp t2)) ==> eq) (fun e : SP.elt => (fstpp e =? p)%positive || (sndpp e =? p)%positive).
proof: Proof. intros p x y Hxy. destruct Hxy as [Hxyf Hxys]. rewrite Hxyf; rewrite Hxys. reflexivity. Qed.
imports: Recdef NArith GeoCoq.Utils.sets