 generalized
method is applied. As with the specialized method, the procedure hinges first
on the values of <code>i</code> and, optionally, <code>j</code>. The work proceeds in steps, by
testing a sequence of possible conditions in sequence.</p><ol><li><p>A check is made as to whether <code>i</code> names one of the standard <code>oce</code> slots.
If so, <code>[[</code> returns the slot contents of that slot.  Thus, <code>x[["metadata"]]</code>
will retrieve the <code>metadata</code> slot, while <code>x[["