proposition: Lemma actKin : {in D, right_loop invg to}.
proof: Proof. by move=> a Da /= x; rewrite -actMin ?groupV // mulgV act1. Qed.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat div seq) mathcomp(fintype bigop finset fingroup morphism perm) mathcomp(automorphism quotient)