fact: Definition suchThatMaybe1 {A : Type} (g : G A) (p : A -> bool) : G (option A) := fmap (fun x => if p x then Some x else None) g.
imports: Coq(String List ZArith Lia) mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool ssrnat eqtype seq) QuickChick(RandomQC RoseTrees Sets Tactics Producer)