title: Nested call to integral fails
body: <p>Try this piece of code, which works fine.</p>
  
  <pre><code>a=1;b=2;
  % A two-variate function 
  f2= @(x,y) x+y;
  derivedF2=@(x) integral(@(y) f2(x,y), a,b);
  % Test the evaluation of the derived function handle
  derivedF2(0);
  % Test the integration of the derived function handle
  % integralVal=integral(derivedF2,a,b);
  % integralVal=integral(@(x) derivedF2(x),a,b);
  % Test plotting of the derived function handle
  figure(11);
  ezplot(derivedF2);
  </code></pre>
  
  <p>But if you uncomment the lines starting with integralVal. The code breaks.</p>
  
  <p>Apparently, the derived function handle does not support integration operation, or have I missed something?</p>