Definition isringfuntocommringfrac (X : commring) (S : @subabmonoid (ringmultabmonoid X)) : @isringfun X (commringfrac X S) (tocommringfrac X S) := isaddmonoidfuntocommringfrac X S ,, ismultmonoidfuntocommringfrac X S.
Require Import UniMath.Algebra.Groups. Require Import UniMath.MoreFoundations.Sets. Require Import UniMath.MoreFoundations.Orders.