English
The tensor product of the identity with itself is the identity on the tensor product space.
Русский
Тензорное произведение единицы с единицей равно единице на произведении пространств.
LaTeX
$$\left(\operatorname{id} \otimes' \operatorname{id}\right) = \left(\operatorname{id} : \alpha \otimes \beta \Rightarrow \_\right)$$
Lean4
theorem prod_id : ∀ {n} {α β : TypeVec.{u} n}, (id ⊗' id) = (id : α ⊗ β ⟹ _) :=
by
intros
ext i a
induction i with
| fz => cases a; rfl
| fs _ i_ih => apply i_ih