This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
(As mentioned in Bug 5267 comment #3.) XDM section 2.6.2 Predefined Types, under xs:anyAtomicType, says: All primitive atomic types, such as xs:integer and xs:string, have xs:anyAtomicType as their base type. but xs:integer is not a primitive atomic type. You could just use a different example, e.g. xs:decimal.
As per your suggestion xs:decimal is used as the example.