Section PgroupProps.
Variable gT : finGroupType.
Implicit Types (pi rho : nat_pred) (p : nat).
Implicit Types (x y z : gT) (A B C D : {set gT}) (G H K P Q R : {group gT}).

Lemma coprime_sdprod_Hall_l G K H : K ><| H = G -> coprime #|K| #|H| = Hall G K.