proposition: Lemma naturality_local : naturality [the functor of Local.acto E \o M] [the functor of M] local.
proof: Proof. by move=> A B h; apply funext => -[]. Qed.
imports: mathcomp(all_ssreflect) imonae_lib HB(structures) ihierarchy imonad_lib ifail_lib istate_lib itrace_lib imonad_transformer