title: Sections - why do I need backticks here?
body: <p>I am trying to understand sections and think I have got it.  Basically it is a way to apply partial application to binary operators.  So I understand all the <code>(2*)</code>, <code>(+1)</code>, etc. examples just fine.</p>
  
  <p>But in the O'Reilly Real World Haskell book, Sections 'section' :) it has this example:</p>
  
  <pre><code>(`elem` ['a'..'z']) 'f'
  &gt;True
  </code></pre>
  
  <p>I understand the need for the parentheses - ie the section syntax.  But why do I need the backticks?</p>
  
  <p>If I try, I get:</p>
  
  <pre><code>(elem ['a'..'z']) 'f'
  
  &lt;interactive&gt;:220:19:
      Couldn't match expected type `[[Char]]' with actual type `Char'
      In the second argument of `elem', namely 'f'
      In the expression: (elem ['a' .. 'z']) 'f'
      In an equation for `it': it = (elem ['a' .. 'z']) 'f'
  </code></pre>