English
The range of the tensor-product map is the submodule generated by products of elements from the ranges of f and g.
Русский
Образ отображения на тензорном произведении равен подмодуля, порожденному произведениями элементов диапазонов f и g.
LaTeX
$$$\\operatorname{range}(\\mathrm{map}\\ f\\ g) = \\mathrm{map_2}(\\mathrm{mk}\\ R\\ P\\ Q)\\ (\\operatorname{range} f)\\ (\\operatorname{range} g).$$$
Lean4
/-- The tensor product of modules is commutative, up to linear equivalence.
-/
protected def comm : M ⊗[R] N ≃ₗ[R] N ⊗[R] M :=
LinearEquiv.ofLinear (lift (mk R N M).flip) (lift (mk R M N).flip) (ext' fun _ _ => rfl) (ext' fun _ _ => rfl)