proposition: Lemma nbhs_EFin (x : R) : (\forall y \near x%:E, P y) <-> \near x, P x%:E.
proof: Proof. done. 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