onding <tt>.nl</tt> file, for instance <tt>chain.nl</tt> stored in directory <tt>datafiles</tt>. All the user has to do to solve the problem is to call the following three commands:
         </p><pre>penm=nlp_define('datafiles/chain100.nl');
prob=penlab(penm);
prob.solve();</pre><p><b>Linear semidefinite programming with SDPA input</b></p>
         <p>Go to directory <tt>interfaces/LMI</tt>. Assume that a linear SDP problem is stored in an SDPA input file, for instance <tt>arch0.dat-s</tt> stored in directo