&amp; pen.mconstr&gt;0)
0085     <span class="keyword">if</span> (~isfield(pen,<span class="string">'msizes'</span>) || any(pen.msizes&lt;1))
0086       error(<span class="string">'Input: msizes missing or wrong.'</span>);
0087     <span class="keyword">end</span>
0088 
0089     <span class="comment">% linear matrix terms - OK?</span>
0090     <span class="keyword">if</span> (isfield(pen,<span class="string">'ai_dim'</span>))
0091       <span class="keyword">if</span> (isempty(pen.ai_dim) || any(pen.ai_dim&