Is xdt:anyAtomicType itself atomic?

	My understanding is that xdt:anyAtomicType type is defined as
	the union of all atomic types and that atomic types are only
	those such as xs:integer, xs:string, etc.

	It would therefore seem to be the case that xdt:anyAtomicType
	itself is not "atomic."

	This makes perfect sense to me, but it is correct?  Or should
	xdt:anyAtomicType itslef also be considered atomic?

	- Paul