Definition zero_lfun : 'Hom(aT, rT) := linfun \0.
Definition add_lfun f g := linfun (f \Fact lfun_addA : associative add_lfun.drA. Qed.

Fact lfun_addC : commutative add_lfun.

(* Specifications: *)
Fact lfun_add0 : left_id zero_lfun add_lfun.