Versioning and nested declarations

Is this allowed:

  <p:declare-step ...>
    <p:declare-step ...>
      <p:import href="http://www.w3.org/2008/xproc-2.0.xpl"/>
      ...
    </p:declare-step>
    ...
  </p:declare-step>

It seems to me that we could say it is allowed, and has the effect of
making the entire pipeline use the 2.0 definitions, or we could say
no, that if you want to use 2.0 definitions inside a nested pipeline
(for example, one you've imported), then you have to also have the
import for that library at the top level.

It seems to me that the tricky part of allowing it is dealing with
steps that you may already have parsed before you see the 2.0 import.
E.g., what if you rejected them because they use new options defined
in 2.0?

On the whole, I think it might be safer to say that nested imports of
new versions are only legal if the new version has already been
imported.

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com> | There is nothing which human courage
http://nwalsh.com/            | will not undertake, and little that
                              | human patience will not endure.--Dr.
                              | Johnson