title: No instance for (Show ([(Char, Char)] -> Char))
body: <p>So I have to make a function that finds a pair with its 1st letter and returning the 2nd letter.</p>
  
  <p>I actually found one answer but with the map function and I couldn't get it.</p>
  
  <pre><code>      lookUp :: Char -&gt; [(Char, Char)] -&gt; Char
        lookUp x [] = x
        lookUp x ( ( st,nd ): rst) | st == x = nd
                     | otherwise = lookUp x rst
  </code></pre>
  
  <p>And I get this message:</p>
  
  <pre><code>No instance for (Show ([(Char, Char)] -&gt; Char))
  arising from a use of `print'
   Possible fix:
    add an instance declaration for (Show ([(Char, Char
    In a stmt of an interactive GHCi command: print it
  </code></pre>