RPSLng and nested refine/except expressions

["Larry J. Blunk" <]

  In the -04 version of the RPSLng draft, the structured policy syntax was
updated to allow nested refines and excepts in policy expressions.  I.e.

  refine {
    <expression>
     refine {
         <expression>
     }
  }

   Examples of such expressions are given both RFC2622 and the RPSLng
draft.   However, the original RFC2622 syntax did not actually allow such
expressions.

   However, in the process of implementing and running the syntax check
on existing objects, I have found examples of the following:

  refine {
     <expression>
     } refine {
        <expression>
     }

     See, for example, AS7574 in the RADB.  Unfortunately, such expressions
are invalid in the lastest RPSLng draft.   Are such expressions semantically
identical to nested refines/excepts?    Should both this form and the nested
form be allowed.    I have come up with a minor modification to the -04
syntax that would allow both, but I'm not sure if it is a good idea or not.

   -Larry