Behold.

\[
\begin{gathered}
{\Gamma \vdash i : \mathbb{Z}}
\qquad
\frac{\Gamma \vdash e_1 : \mathbb{Z} \quad
\Gamma \vdash e_2 : \mathbb{Z}}
{\Gamma \vdash e_1 + e_2 : \mathbb{Z}}
\end{gathered}
\]

Now with code block!

let f (x : int) (y : int) =
  x + y