[Bug 4526] [UPD] Sections 2.4.*: Target should allow empty sequence

http://www.w3.org/Bugs/Public/show_bug.cgi?id=4526

           Summary: [UPD] Sections 2.4.*: Target should allow empty sequence
           Product: XPath / XQuery / XSLT
           Version: Working drafts
          Platform: PC
        OS/Version: Windows XP
            Status: NEW
          Severity: critical
          Priority: P2
         Component: Update Facility
        AssignedTo: andrew.eisenberg@us.ibm.com
        ReportedBy: mrys@microsoft.com
         QAContact: public-qt-comments@w3.org


Update target should allow empty sequence to make this usable in a static
typing context. Semantics where target is empty is a no-op.

Currently an expression such as (/a/b)[1] as a target will most likely fail
because it is statically typed as b?.