proposition: Lemma picksP (T : finType) (A : {set T}) : picks_spec A [pick x in A].
proof: Proof. case: pickP => /= [|eq0]; first exact: Picks. apply/Nopicks/setP => x. by rewrite !inE eq0. Qed.
imports: Coq(Setoid Morphisms) mathcomp(all_ssreflect) GraphTheory(edone)