XQuery type system

XQuery is a strongly typed language in which the operands of various expressions, operators, and functions conform to expected types.

The type system for XQuery includes a subset of the built-in types of XML schema and the predefined types of XQuery.

The built-in types of XML Schema are in the namespace http://www.w3.org/2001/XMLSchema, which has the predeclared namespace prefix xs. Some examples of built-in schema types include xs:integer and xs:string.