Syntax
BD>adjust : [- / D + D + ...+ D ]
where are the names of bases or
elements.
In addition to adding quantities to a fit, we can withdraw them. This
form of the command assumes that there is a current adjustment: suppose
that it is where B is the collection being
adjusted; are collections which have been fitted
explicitly, and F comprises the remaining collections fitted. The
effect of the command is now to carry out the adjustment
(dropping ), which becomes the new
current adjustment. The difference between this and the previous
adjustment is a partial adjustment which quantifies the effect of losing
as an information source. This process continues, dropping a
at each stage until the final current adjustment is
.
The base notation discussed in §9.1.2 may be used. Any base
which is presented for use during an adjustment must contain
only elements having beliefs, and no data elements.
Note that influence diagrams
are not drawn when withdrawing quantities from an adjustment.
We emphasize that bases being withdrawn must have been explicitly added.
That is, the following sequence of commands is not useful:
as the base D3 would not have been explicitly fitted during the
current adjustment, and so cannot be removed.