proposition: Lemma entourage_ballE {R : numDomainType} {M : pseudoMetricType R} : entourage_ (@ball R M) = entourage.
proof: Proof. by rewrite entourageE_subproof. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed