title: What is wrong with this simple type definition? (Expecting one more argument to...)
body: <p>basic.hs:</p>
  
  <pre><code>areaCircle :: Floating -&gt; Floating
  areaCircle r = pi * r * r
  </code></pre>
  
  <p>Command:</p>
  
  <pre><code>*Main&gt; :l basic.hs 
  [1 of 1] Compiling Main             ( Sheet1.hs, interpreted )
  
  Sheet1.hs:2:15:
      Expecting one more argument to `Floating'
      In the type signature for `areaCircle':
        areaCircle :: Floating -&gt; Floating
  Failed, modules loaded: none.
  </code></pre>
  
  <p>I see that <code>areaCircle :: Floating a =&gt; a -&gt; a</code> loads as expected. Why is the above version not acceptable?</p>