{G H K : Group} (f : K $-> G) (g : K $-> H) : K $-> (grp_prod G H). Proof. snrapply Build_GroupHomomorphism. - exact (fun x : K => (f x, g x)). - intros x y. apply path_prod'; apply grp_homo_op. Defined.
Require Import Basics Types HProp HFiber HSet. Require Import Homotopy.IdentitySystems. Require Import (notations) Classes.interfaces.canonical_names. Require Import Pointed.Core. Require Import WildCat. Require Import Spaces.Nat.Core Spaces.Int. Require Import Truncations.Core.