nm.congrad = @ex1_congrad;
  penm.objhess = @ex1_objhess;
  penm.conhess = @ex1_conhess;
<span class="keyword">end</span>
</pre><p>To solve this example, we execute the following commands:</p><pre>penm = ex1_define;
prob = penlab(penm);
prob.solve();
x = prob.x;</pre><p><b>Example 2</b> Next, consider a toy nonlinear SDP example in two variables
         </p>
         <p><img src="manual_eq91785.png" alt="$$ \min \frac{1}{2}(x_1^2 + x_2^2)$$"></p>
         <p>subject to</p>
         <p><img src="manual_eq16