object relations to generate the desired sequence of objects.

An example can be found in "app/gui.l", in the 'choOrd' function which
implements the search dialog for <code>+Ord</code> (order) objects. Orders can
be searched for order number and date, customer name and city, item description
and supplier name:

<pre>
(select (@@)
   ((nr +Ord @Nr) (dat +Ord @Dat)
      (nm +CuSu @Cus (cus +Ord))
      (ort +CuSu @Ort (cus +Ord))
      (nm +Item @Item (itm +Pos) ord)
      (nm +CuSu @Sup (sup +Item) (itm +Po