English
There is an R-algebra isomorphism between A[X] and A ⊗R R[X] given by the pair (toFunAlgHom, invFun) with the stated inverses.
Русский
Существуют R-алгебраическое изоморфизм между A[X] и A ⊗R R[X], заданный парой (toFunAlgHom, invFun) с указанными обратными.
LaTeX
$$polyEquivTensor : A[X] ≃ₐ[R] A ⊗[R] R[X] with toFunAlgHom and invFun$$
Lean4
/-- (Implementation detail)
The equivalence, ignoring the algebra structure, `(A ⊗[R] R[X]) ≃ A[X]`.
-/
def equiv : A ⊗[R] R[X] ≃ A[X] where
toFun := toFunAlgHom R A
invFun := invFun R A
left_inv := left_inv R A
right_inv := right_inv R A