\begin{document}
+ \begin{section}{Algebra}
+ If $R$ is a commutative ring, then $\polyring{R}{X,Y,Z}$ is a
+ multivariate polynomial ring with indeterminates $X$, $Y$, and
+ $Z$, and coefficients in $R$. If $R$ is a moreover an integral
+ domain, then its fraction field is $\Frac{R}$.
+ \end{section}
+
\begin{section}{Algorithm}
An example of an algorithm (bogosort) environment.
domain, then the preimage under $f$ of $A$ is $\preimage{f}{A}$.
\end{section}
+ \begin{section}{Calculus}
+ The gradient of $f : \Rn \rightarrow \Rn[1]$ is $\gradient{f} :
+ \Rn \rightarrow \Rn$.
+ \end{section}
+
\begin{section}{Common}
The function $f$ applied to $x$ is $f\of{x}$. We can group terms
like $a + \qty{b - c}$ or $a + \qty{b - \sqty{c - d}}$. Here's a