<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">\begin{slide}{Generische Instanzen}

\begin{verbatim}
instance Show a =&gt; Show ( Maybe a ) where
    show m = case m of
        Nothing -&gt; "Nothing"
        Just x  -&gt; "Just" ++ show x
\end{verbatim}

das kann der Compiler selbst:
\begin{verbatim}
data Maybe a = ... 
    deriving ( Show )
\end{verbatim}

\end{slide}
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