anyAtomicType data type
The
xdt:anyAtomicType data type denotes a context where any atomic type
can be used. This data type serves as the base type for all atomic
types. An instance of an atomic type is a single nondecomposable value
such as an integer, a string, or a date. Derived from the xs:anySimpleType
data type.
The data type xdt:anyAtomicType has an unconstrained lexical form.
Casting is not supported to or from the xdt:anyAtomicType data type.