Definition sieve_selected_morphism_domain : C := pr1 f.
Require Import UniMath.Foundations.All. Require Import UniMath.CategoryTheory.Categories.HSET.Core. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.CategoryTheory.opp_precat. Require Import UniMath.CategoryTheory.Presheaf. Require Import UniMath.CategoryTheory.Subobjects. Require Import UniMath.CategoryTheory.yoneda. Require Import UniMath.CategoryTheory.Monics.