[xacml] Function Document Issues

I think we have the following issues that need some type of resolution:

1. Everywhere we have [NEED SPECIFICATION] in the document we need a
   specification to refer to, or we must create our own. These
   specifications are for such functions as  string-equals, string-match,
   string-greater-than, datetime-greater-than, x500Name-equals, etc.

   Does anybody have anything to point for all these things, or
   formal descriptions for these things? Please look over the document.

2. "and" and "or", "n-of" functions. I think they are unnecessary in
   contrast to their "ordered-*" counterparts. Since we are now
   paying explicit attention to ERROR when evaluating policy, I think we
   should just go with the "ordered" versions of these functions for
   explicitly determinate results.

3. What is the type of an argument to the function "present".
   What does it look like?  Someone please give me an example.

Cheers,
-Polar