∀ {ι : Type u_1} [inst : Fintype ι] {M : Type u_2} [inst_1 : AddCommGroup M] (R : Type u_3) [inst_2 : CommRing R]
  [inst_3 : Module R M] (b : ι → M) [inst_4 : DecidableEq ι] (hb : Submodule.span R (Set.range b) = ⊤)
  (A : ↥(Matrix.isRepresentation R b)) {f : Module.End R M},
  Matrix.Represents b (↑A) f → (Matrix.isRepresentation.toEnd R b hb) A = f