Section Basic.
Variable S : {group gT}.
Hypotheses (pS : p.-group S) (esS : extraspecial S).
Let pZ : p.-group 'Z(S) := pgroupS (center_sub S) pS.
End Basic.

Lemma p3group_extraspecial G :
p.-group G -> ~~ abelian G -> logn p #|G| <= 3 -> extraspecial G.