Done: ACTION A-636-06

I decided to resolve this by changing this text:

If the content expression<https://email.emc.com/OWA/?ae=Item&a=New&t=IPM.Note&cc=MTQuMy4yNjYuMSxlbi1VUyw0Mjk0OTY3Mjk1LEhUTUwsMCww&pspid=_1460473043860_549547551#dt-content-expression> is omitted, the value of the content expression is ().
to:
If the content expression is not provided explicitly, the content expression is ().
Previously, no content expression was provided, but the value of the content was specified. This caused problems evaluating functions with empty bodies, and failed to provide a host language expression for the function implementation in the data model.

Jonathan

ACTION A-636-06:  Jonathan to ensure that the classification of functions
implemented by an XQuery expression covers the case where the function
body is empty.
**See:
https://lists.w3.org/Archives/Public/public-xsl-query/2016Mar/0040.html