title: SOS optimization; how to determine which constraints are empty?
body: <p>I am using SOS optimization to solve an adaptive control problem using the inverse Lyapunov method. I have been successful in obtaining the Lyapunov function and region of attraction level-set for some simple problems. Now, I am trying to determine the Lyapunov for a new system. I am getting the error &quot;Constraint ### is empty.&quot;, where ### is a number that changes randomly. How do I debug which constraint is empty? My constraints look like the following:</p>
  <pre><code>prog.AddSosConstraint( V-l1 )
  prog.AddSosConstraint( -((beta-h)*p1 + V-1) )
  prog.AddSosConstraint( -(l2+Vdot) + p2*(V-1))
  </code></pre>
  <p>p1 and p2 have the decision variables. V, l1, and l2, are functions for the indeterminants only.
  I am following the iterative procedure in [1] to solve for the Lyapunov function and region of attraction level-set.</p>
  <p>[1] F. Meng, D. Wang, P. Yang, G. Xie and F. Guo, &quot;Application of Sum-of-Squares Method in Estimation of Region of Attraction for Nonlinear Polynomial Systems,&quot; in IEEE Access, vol. 8, pp. 14234-14243, 2020, doi: 10.1109/ACCESS.2020.2966566.</p>