English
For a linear map f, a polynomial q, and r ∈ R, eval r (map R f q) = f (eval r q).
Русский
Для линейного отображения f, полинома q и r ∈ R, eval r (map R f q) = f (eval r q).
LaTeX
$$$\\operatorname{eval} r (\\operatorname{map} R f q) = f \\big( \\operatorname{eval} r q \\big)$$$
Lean4
@[simp]
theorem eval_map (f : M →ₗ[R] M') (q : PolynomialModule R M) (r : R) :
eval (algebraMap R R' r) (map R' f q) = f (eval r q) := by
induction q using induction_linear with
| zero => simp_rw [map_zero]
| add f g e₁ e₂ => simp_rw [map_add, e₁, e₂]
| single i m => simp only [map_single, eval_single, f.map_smul]; module