proposition: Lemma map_rfix_mx H : (rfix_mx rG H)^f = rfix_mx rGf H.
proof: Proof. rewrite map_kermx //; congr (kermx _); apply: map_lin1_mx => //= v. rewrite map_mxvec map_mxM; congr (mxvec (_ *m _)); last first. by apply: map_lin1_mx => //= u; rewrite map_mxM map_vec_mx. by apply/row_matrixP=> i; rewrite -map_row !rowK map_mxvec map_mxB map_mx1. 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)