"XPath 1.0 has a special data type called Result Tree Fragments" is certanly a typo. Should be read as
"XSLT 1.0 has a special data type called Result Tree Fragments"
You're right, my mistake. http://www.w3.org/TR/xslt#section-Result-Tree-Fragments makes it clear that XSLT adds this "data type" to the four defined in XPath that it can already use.
You're right, my mistake. http://www.w3.org/TR/xslt#section-Result-Tree-Fragments makes it clear that XSLT adds this "data type" to the four defined in XPath that it can already use.