proposition: Lemma filter_from_normE (x : V) (P : V -> Prop) : @filter_from R _ [set x : R | 0 < x] (ball_norm x) P = \near x, P x.
proof: Proof. by rewrite filter_from_norm_nbhs. 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