xml literal lex space question

A question has come up on comments.  Is "<ex/>" in the lexical space 
rdf:XMLLiteral.  I believe not, it must be "<ex></ex>", but wanted to check.

The text in concepts is:

http://www.w3.org/2001/sw/RDFCore/TR/WD-rdf-concepts-20030117/#section-XMLLiteral

[[
The lexical space
     is the set of all strings which:

         * are well-balanced, self-contained XML data [XML];
         * correspond to exclusive Canonical XML (with comments, with 
empty InclusiveNamespaces PrefixList ) [XML-XC14N];
]]

The corresponds to will need clarification.

Brian