proposition: Lemma acompsP K s : reflect (last K s = 1%G /\ path [rel x y : {group rT} | maxainv x y] K s) (acomps K s).
proof: Proof. by apply: (iffP andP); case; move/eqP. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype bigop finset fingroup morphism) mathcomp(automorphism quotient action gseries)