There are three possible options to use for the calculational mode. The
first uses only the values 0 and 1 and is equivalent to "YES" and "NO".
When running the rules, the first time a choice is in a valid THEN or ELSE
part, the value sets the values of the choice for that run.

A second system, and the most generally useful, is the system that uses
values between 0 and 10.  The values 0 and 10 are equivalent to "absolutely
no" and "absolutely yes".  The values from 1 to 9 are degrees of certainty
from "very probably no" to "very probabily yes".  The values 0 and 10 lock
the value for the choice to that value, regardless of other values the
choice may have received.  The values from 1 to 9 are averaged over the
rules that are used to arrive at the final value for a choice.

The third and most complicated system uses values from -100 to 100, which
indicate degrees of certainty, or negative certainty. The values DO
NOT lock the value as 0 and 10 do in the 0-10 system.  All values are
considered in the final calculation which can be an average of the values
found or the values can be combined as dependent or independent
probabilities.
