proposition: Lemma Zisometry_inj A nu : {in 'Z[S, A] &, isometry nu} -> {in 'Z[S, A] &, injective nu}.
proof: Proof. by move/isometry_raddf_inj; apply; apply: rpredB. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div choice fintype tuple finfun bigop prime order) mathcomp(ssralg poly finset fingroup morphism perm) mathcomp(automorphism quotient finalg action gproduct) mathcomp(zmodp commutator cyclic center pgroup sylow) mathcomp(frobenius vector ssrnum ssrint archimedean intdiv) mathcomp(algC algnum classfun character integral_char)