 relations, or tree relations like
<code><a href="refR.html#+Ref">+Ref</a></code> to arrive at database objects
with a type suitable for return values from <code>select</code>.

<p>To locate appropriate objects from associated objects, the generator clause
can contain - in addition to the standard relation/class/pattern specification
(see <a href="#gencl">Generator Clauses</a> above) - an arbitrary number of
association specifiers. Each association specifier can be

<ol>
<li>A symbol. Then a <code><a href="