proposition: Lemma flat_map_empty : forall {A B} s, @flat_map A B (fun _ => []) s = [].
proof: Proof. induction s; firstorder. Qed.
imports: Fiat.Common.Coq__8_4__8_5__Compat Coq.ZArith.ZArith Coq.Lists.List Coq.Lists.SetoidList Coq.Bool.Bool Fiat.Common Fiat.Common.List.Operations Fiat.Common.Equality Fiat.Common.List.FlattenList Fiat.Common.LogicFacts