Definition K_0_related {M:ExactCategory} (E : ShortExactSequence M) : K_0_hrel M (free_abgr_unit (component (Ob2 E))) (free_abgr_unit (component (Ob1 E)) + free_abgr_unit (component (Ob3 E))) := hinhpr ( E ,, idpath _ ,, idpath _).
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.Algebra.Groups. Require Import UniMath.Algebra.Free_Monoids_and_Groups.