Section Equiv_VS.
Context {T : Type} {K : AbsRing} {V : NormedModule K}.
End Equiv_VS.
(** * Multiplication and inverse *)
(** Domination *)
(** Equivalence *)

Lemma equiv_inv :
forall {T} {F : (T -> Prop) -> Prop} {FF : Filter F} (f g : T -> R),
F (fun x => g x <> 0) -> is_equiv F f g ->
is_equiv F (fun x => / f x) (fun x => / g x).