English
The polynomial ring in finitely many variables over a finitely presented algebra is finitely presented.
Русский
Кольцо многочленов в конечном числе переменных над конечной презентацией алгебры сохраняет конечную презентацию.
LaTeX
$$$[\\text{FinitePresentation } R A] \\Rightarrow \\text{FinitePresentation } R (A[X])$$$
Lean4
/-- `R[X]` is finitely presented as `R`-algebra. -/
instance polynomial [FinitePresentation R A] : FinitePresentation R A[X] :=
letI := FinitePresentation.mvPolynomial R A Unit
have := equiv (MvPolynomial.pUnitAlgEquiv.{_, 0} A)
.trans _ A _