English
The multiplication on the tensor product A ⊗_R B is given by a bilinear map: mul: (A ⊗_R B) → (A ⊗_R B) → (A ⊗_R B).
Русский
У тензорного произведения A ⊗_R B имеется умножение, заданное двугубым билинейным отображением mul.
LaTeX
$$$ \text{mul} : (A \otimes_R B) \to (A \otimes_R B) \to (A \otimes_R B) \quad \text{(bilinear)} $$$
Lean4
/-- (Implementation detail)
The multiplication map on `A ⊗[R] B`,
as an `R`-bilinear map.
-/
@[irreducible]
def mul : A ⊗[R] B →ₗ[R] A ⊗[R] B →ₗ[R] A ⊗[R] B :=
TensorProduct.map₂ (LinearMap.mul R A) (LinearMap.mul R B)