proposition: Lemma sub1_scale_ball A l : is_ball A -> A `<=` l.+1%:R *` A.
proof: Proof. by move/scale_ball1 => {1}<-; apply: sub_scale_ball; rewrite ler1n. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrint ssrnum finmap matrix) mathcomp(rat interval zmodp vector fieldext falgebra) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality set_interval Rstruct) ereal reals signed topology prodnormedzmodule