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Subject: Ordered Combinators


I would still like to issue a caution to these ordered Permit-Overrides
and Deny-Overrides. 

The current combinator algorithms imply that it may return
Permit-Indeterminate, Deny-Indeterminate, or NotApplciable-Indeterminate
based on the availability of the arguments or errors in evaluating their
consitiuents, being careful to make sure one does not return the wrong
thing, i.e. Deny in the face of and Indeterminate in Permit-Overrides, or
Permit in the face of an Indterminate in Deny-Overrides

So, why the ordered combinators?

Is it only there to make sure that if you are evaluating in the face of
errors or availability of arguments, so that you will get the same answer
from different implementations based on the same inputs/availability or
error conditions?

This requires a lot more than just specifying an ordering to the combining 
algorithm. Otherwise, you are giving a "false sense of integrity." I think 
you are biting off more than you can chew.

In PolicySets, this requires that all Policies be evaluated by the same
evaluation engine. If a "sub" policy's combinator evaluates a rule that
generates an Indeterminate, then the PolicySet may return Indeterminate.  
However, under another implementation although the same "sub" policy will
get evaluated at the same point, but indeterminate may not be the case due
to a different evaluation of the rules of the "sub" policy, but you have
no real control of this.

So, I think it that really doesn't take the problem you are seeking to

Also, I'm a little concerned about the definitions of and, or, and n-of,
which also affects this.  I'll write that under a separate thread.


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