title: Why complains Haskell parse error on input `|' in this Function?
body: <p>I was supposed to write a little function in Haskell, which should erase elements, which are twice in the list. Unfortunately, Haskell complains " parse error on input `|' ". Could anyone help me with that?</p>
  
  <pre><code>makeSets=mSet[]s
           where 
              mSet stack []=stack
              mSet stack (x:xs)
                               |contains stack x=mSetstack xs
                               | otherwise =mSet (x:stack) xs
                                            where 
                                                  contains [] thing=False
                                                  contains (x:xs)thing
                                                                       | x==thing=True
                                                                       |otherwise=contains xs thing
  </code></pre>