English
The tensor product M ⊗_R N carries a natural additive monoid structure, compatible with the tensor product operations.
Русский
Тензорное произведение M ⊗_R N имеет естественную структуру аддитивного моноида, совместимую с тензорной операцией.
LaTeX
$$$\text{AddMonoid}(M \otimes_R N)$$$
Lean4
instance addMonoid : AddMonoid (M ⊗[R] N) :=
{
TensorProduct.addZeroClass _ _ with
toAddSemigroup := TensorProduct.addSemigroup _ _
toZero := TensorProduct.zero _ _
nsmul := fun n v => n • v
nsmul_zero := by simp [TensorProduct.zero_smul]
nsmul_succ := by simp only [TensorProduct.one_smul, TensorProduct.add_smul, add_comm, forall_const] }