proposition: Lemma memmx_cent_envelop : (f \in 'C(E_G))%MS = centgmx rG f.
proof: Proof. apply/cent_rowP/centgmxP=> [cfG x Gx | cfG i]. by have:= cfG (enum_rank_in Gx x); rewrite rowK mxvecK enum_rankK_in. by rewrite rowK mxvecK /= cfG ?enum_valP. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div choice fintype tuple finfun bigop prime) mathcomp(ssralg poly polydiv finset fingroup morphism) mathcomp(perm automorphism quotient finalg action zmodp) mathcomp(commutator cyclic center pgroup matrix mxalgebra) mathcomp(mxpoly)