proposition: Lemma morphim_p_group P : p_group P -> p_group (f @* P).
proof: Proof. by move/morphim_pgroup; apply: pgroup_p. Qed.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq div) mathcomp(fintype bigop finset prime fingroup morphism) mathcomp(gfunctor automorphism quotient action gproduct) mathcomp(cyclic)