[Bug 4578] [FS] Possible error in filter expression normalization rules

http://www.w3.org/Bugs/Public/show_bug.cgi?id=4578

           Summary: [FS] Possible error in filter expression normalization
                    rules
           Product: XPath / XQuery / XSLT
           Version: Recommendation
          Platform: PC
        OS/Version: Windows NT
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Formal Semantics
        AssignedTo: jmdyck@ibiblio.org
        ReportedBy: tim@cbcl.co.uk
         QAContact: public-qt-comments@w3.org


In 4.3.2 Filter Expressions the rule

[PrimaryExpr PredicateList [ fn:last() ]]Expr
==
let $fs:sequence := [PrimaryExpr PredicateList]Expr return
fn:subsequence($fs:sequence, $fs:last,1)

doesn't define fs:last.  I suspect it should be:

[PrimaryExpr PredicateList [ fn:last() ]]Expr
==
let $fs:sequence := [PrimaryExpr PredicateList]Expr return
let $fs:last := fn:count($fs:sequence) return
fn:subsequence($fs:sequence, $fs:last,1)