English
The subalgebra generated by the image of M under ι_R is the whole tensor algebra; i.e., the range of ι_R generates TensorAlgebra R M as an algebra.
Русский
Подалгебра, порождаемая образом M через ι_R, равна всей TensorAlgebra R M; диапазон ι_R порождает алгебру.
LaTeX
$$$\\operatorname{adjoin}_R\\bigl(\\mathrm{Set.range}(\\iota_R\\ (M))\\bigr) = \\top$$$
Lean4
@[simp]
theorem adjoin_range_ι : Algebra.adjoin R (Set.range (ι R (M := M))) = ⊤ :=
by
refine top_unique fun x hx => ?_; clear hx
induction x using induction with
| algebraMap => exact algebraMap_mem _ _
| add x y hx hy => exact add_mem hx hy
| mul x y hx hy => exact mul_mem hx hy
| ι x => exact Algebra.subset_adjoin (Set.mem_range_self _)