\section{lhs test}\label{lhs-test}

\texttt{unsplit} is an arrow that takes a pair of values and combines them to
return a single value:

\begin{code}
unsplit :: (Arrow a) => (b -> c -> d) -> a (b, c) d
unsplit = arr . uncurry
          -- arr (\op (x,y) -> x `op` y)
\end{code}

\texttt{(***)} combines two arrows into a new arrow by running the two arrows on a
pair of values (one arrow on the first item of the pair and one arrow on the
second item of the pair).

\begin{verbatim}
f *** g = first f >>> second g
\end{verbatim}

Block quote:

\begin{quote}
foo bar
\end{quote}