Intersection use case

I know from one source that a given server understands WS-Addressing and
can handle non-anonymous response endpoints.  Furthermore, this source
tells us that said endpoints must have either HTTP or Jabber
destinations.  (for concreteness, you might think of this as a default
behavior for a site)

>From another source, we learn that this same server's non-anonymous
response endpoints must have either Jabber or Mailto destinations. (and
this might be further description of the particular server)

Combining the information from these sources, we conclude that said
non-anonymous endpoints must have Mailto destinations.

How do we express all this in WSP?  In particular, can we use policy
intersection to combine the information from the two sources and get the
expected result.

Variant:  Instead of "must have" the sources tell us that the EPRs "may
have" the given kind of destination.  The combined information is thus
that the destinations may be HTTP, Jabber /or/ mailto.

Further variants: It seems reasonable for sources of information to be
able to say things like "must not have ...", or for one source to say
"must have HTTP or Jabber" and another to say "must not have jabber".