title: Error:Malformed head of type or class declaration
body: <p>I tried the following code in ghci in ubuntu.</p>
  
  <pre><code>data Btree a=Ebt|Node a (Btree a)(Btree a)
  t=Node 10( Node 20 Ebt Ebt) (Node 30 Ebt Ebt)
  </code></pre>
  
  <p>The compiler shows the error: <code>Malformed head of type or class declaration</code></p>
  
  <p>The compiler compiles others code well. Can you please help me to find out the problem?</p>