I ran the following query using BaseX 9.3.3 command-line client:

'hello' instance of xs:anyAtomicType

the result of the query is `true`.

But if I run this query:

'hello' instance of xs:anySimpleType

an error "[XPST0051] Unknown type: xs:anySimpleType" is returned

Similarly, for the query:

'hello' instance of xs:anyType

an error "[XPST0051] Unknown type: xs:anyType" is returned  

Should xs:anySimpleType and xs:anyType be recognized?

Thank you,

Yasir