English
The construct PolyEquivTensor provides an R-algebra equivalence between A[X] and A ⊗R R[X], built from toFunAlgHom and invFun.
Русский
Конструкция PolyEquivTensor обеспечивает R-алгебраическое эквивиалент между A[X] и A ⊗R R[X], построенное на toFunAlgHom и invFun.
LaTeX
$$PolyEquivTensor R A : A[X] ≃ₐ[R] A ⊗[R] R[X]$$
Lean4
/-- The `R`-algebra isomorphism `A[X] ≃ₐ[R] (A ⊗[R] R[X])`.
-/
def polyEquivTensor : A[X] ≃ₐ[R] A ⊗[R] R[X] :=
AlgEquiv.symm { PolyEquivTensor.toFunAlgHom R A, PolyEquivTensor.equiv R A with }