English
The tensor product ⨂[R] i, A_i, where each A_i is a commutative ring and an R-algebra, carries a natural commutative ring structure; i.e., the tensor product of a family of commutative rings is a commutative ring.
Русский
Тензорное произведение семейства коммутативных колец над R имеет естественную структуру коммутативного кольца.
LaTeX
$$⊗[R] i, A_i ∈ CommRing$$
Lean4
instance instCommRing : CommRing (⨂[R] i, A i)
where
__ := instCommSemiring
__ := inferInstanceAs <| AddCommGroup (⨂[R] i, A i)