proposition: Lemma gauge_refl A : gauge A -> [set fg | fg.1 = fg.2] `<=` A.
proof: Proof. case=> n _; apply: subset_trans => -[_ a]/= ->. by apply: entourage_refl; exact: iter_split_ent. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed