XPath / XPtr conformance

Folks,

My cursory read of the archives didn't clarify my understanding of
conformance...

If I have an XML processing application that needs to express linking just
to the extent of XPtr, but doesn't wish to support the many functions
described by XPath, will this make my XPtr support non-conforming? (I want /
need XPtr in my apps, I don't want / need the functions described by XPath)

The intro-paragraphs of XPtr states that it builds upon XPath -- this
implies that XPtr is a superset.  The conformance section states that
conformance is based upon supporting the syntax and all-conforming XPtr
strings.  Does this imply support for all functionality that is described in
XPath?

Regards,

Gavin.