  The aim of the paper is to prove two conjectures that the (left and right)
global dimension of the algebra of polynomial integro-differential operators
$\mathbb{I}_n$ and the Jacobian algebra $\mathbb{A}_n$ is equal to $n$ (over a
field of characteristic zero). An analogue of Hilbert's Syzygy Theorem is
proven for them. The algebras $\mathbb{I}_n$ and $\mathbb{A}_n$ are neither
left nor right Noetherian. Furthermore, they contain infinite direct sums of
nonzero left/right ideals and are not domains. It is proven that the global
dimension of all prime factor algebras of the algebras $\mathbb{I}_n$ and
$\mathbb{A}_n$ is $n$ and the weak global dimension of all the factor algebras
of $\mathbb{I}_n$ and $\mathbb{I}_n$ is $n$.
