proposition: Lemma prelift_repr rD : prelift (repr (\pi_{freeg K / R} rD)) = prelift rD.
proof: Proof. by rewrite (prelift_perm_eq (perm_eq_fgrepr _)). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order generic_quotient) mathcomp(ssralg ssrnum ssrint)