/a>
<li><a href="#univar">Unification Variables</a>
<li><a href="#gencl">Generator Clauses</a>
   <ul>
   <li><a href="#db">B-Tree Stepping</a>
   <li><a href="#interaction">Interaction of Generator Clauses</a>
   <li><a href="#combined">Combined Indexes</a>
   <li><a href="#associations">Indirect Object Associations</a>
   <li><a href="#nested">Nested Pilog Queries</a>
   </ul>
<li><a href="#filcl">Filter Clauses</a>
   <ul>
   <li><a href="#little">A Little Report</a>
   <li><a href="#filpr">Filter Predic