It might be possible to combine AnySimpleType and AnyAtomic, but both
terminologies are used. In DFDL we don't talk of Atomic's much, but
lots of XPath and XML Schema materials do, so we have these two types
that are very similar really.
There is a type union feature in DFDL, and perhaps the difference between
AnyAtomic and AnySimpleType is that AnySimpleType admits XSD unions and list types,
where AnyAtomic does not?
It might be possible to combine AnySimpleType and AnyAtomic, but both terminologies are used. In DFDL we don't talk of Atomic's much, but lots of XPath and XML Schema materials do, so we have these two types that are very similar really.
There is a type union feature in DFDL, and perhaps the difference between AnyAtomic and AnySimpleType is that AnySimpleType admits XSD unions and list types, where AnyAtomic does not?