Section Dprodm.
Variables G H K : {group gT}.
Variables (fH : {morphism H >-> rT}) (fK : {morphism K >-> rT}).
Hypothesis eqHK_G : H \x K = G.
Hypothesis cfHK : fK @* K \subset 'C(fH @* H).

Lemma dprodm_eqf : {in H :&: K, fH =1 fK}.