| SAXONICA | 
The fn:dateTime function has been changed so that if either argument is an empty sequence,
            the result is an empty sequence. This implements a late change to the specification: see W3C bugzilla entry 3651.
         
The old xdt namespace is no longer supported. (The types previously in this namespace
            are now in the XML Schema namespace http://www.w3.org/2001/XMLSchema).
         
A new extension function saxon:sort has been introduced to allow sorting in free-standing XPath
            applications. There are two variants: a single argument version which simply sorts a sequence of nodes or atomic
            values on the value itself (after atomization in the case of a node), and a two-argument version whose second
            argument is an expression (obtained by calling saxon:expression()) that is used to calculate the sort key.
         
An enhancement to the saxon:transform extension function allows parameters to be supplied to
            the transformation. This is done by introducing an optional parameter whose value is a sequence of nodes
            (typically elements): the name of the node is used as the name of a parameter, and the atomized value of the node
            is used as the value of the parameter.
         
The Saxon-SA extension functions saxon:index and saxon:find have been rewritten to use the
            same indexing logic as is used for implicitly-created indexes. A consequence is that the order of results (which has
            never been well-defined) may be different from before.
         
The function iri-to-uri() now escapes ASCII characters that are disallowed in
            an IRI value, specifically the characters space, double-quotation-mark, less-than, greater-than, 
            backslash, circumflex, grave accent, left curly brace, vertical bar, and right curly brace.