The conversion of a simpleMapExpr of the form
PathExpr1 | PathExpr2 | PathExpr3
requires rather a lot of markup.
Because simpleMapExpr is not itself a pathExpr, you end up with (roughly)
which seems excessively verbose (even for XQueryX!).
Is this intentional, or have I missed something?
Thanks for the comment. I cannot recall just now why it was necessary to make simpleMapExpr a sequenceExpt and not a pathExpr, but I suspect it was because I couldn't make it work as a pathExpr. Or maybe it was because I didn't really think of the possibility.
If you have a firm proposal to make a change to the XQueryX 3.0 schema and stylesheet that accomplishes the goal of retaining the current semantics without all of that syntax, please make that proposal. There is certainly not much time remaining to do so, and I am personally out of time before leaving on a nearly 3-week international standards trip.
I'm leaving this bug open (although it was tempting to mark it RESOLVED/WONTDO) in case you do have a detailed proposal in mind.
I'd suggest allowing simpleMapExpr to contain a sequence of two or more pathExpr, mirroring the XQuery grammar:
 SimpleMapExpr ::= PathExpr ("!" PathExpr)*
(I've gone for 2 or more, rather than one or more, but I don't think it matters).
<xsd:sequence minOccurs="2" maxOccurs="unbounded"/>
Here's the corresponding change to the transformation.
<xsl:for-each select="xqx:pathExpr[position() != 1]">
<xsl:apply-templates select="." />
The XML Query WG agreed during its teleconference of 2013-09-26 to make the changes that you propose in Comment 2. Those changes have been made and are visible at http://www.w3.org/XML/Group/qtspecs/specifications/xqueryx-30/html/Overview.html
As a result of this decision and those changes, I have marked this bug RESOLVED/FIXED.
The XQueryX 3.0 document will be reverted to Last Call WD, in which the status section will identify this specific change. If no negative comments are received during the three-week Last Call review period, XQueryX 3.0 will be advanced directly to Proposed Recommendation.
If you are satisfied with this action, please indicate by marking this bug CLOSED.