Code background grey, use special code-block for GHCi

VL1/content/VL1_lists4.tex

@@ -7,13 +7,13 @@ $S = \{2 \times x\ |\ x \in \mathbb{N},\ x \leq 10\}$
 \\
 How does this look in haskell?
 \pause
-\begin{haskellcode}
+\begin{haskellcode*}{bgcolor=mygrey,frame=single,numbers=none,label=GHCi}
 > [ 2 * x | x <- [1..10]]
-\end{haskellcode}
+\end{haskellcode*}
 \pause
 Now let's say we want all numbers between 50 and 100 that have the remainder 0 when divided by 12:
 \pause
-\begin{haskellcode}
+\begin{haskellcode*}{bgcolor=mygrey,frame=single,numbers=none,label=GHCi}
 > [x | x <- [50..100], mod x 12 == 0]
-\end{haskellcode}
+\end{haskellcode*}
 \code{x <- [50..100]} is the binding, while \code{mod x 12 == 0} is the predicate, separated by a comma. We can have multiple predicates.