[xacml] Current Formalism

[Polar Humenn <polar@syr.edu>]

An ApplicablePolicy evaluates to True, False, or Inapplicable.

It is the job of the PDP to map these values to Permit, Deny, or
Indeterminate, which is an adminstrative policy of the PDP.

The most likely would be,

Policy         Result
------         ------
True           Permit
False          Deny
Inapplicable   Indeterminate, or a "default" of Permit, Deny

-Polar