Variable or parameter declarations and mashup statements that define the structure of the result returned by that statement can include the literal XML structure of the content and literal data. While the XML in a variable declaration body is taken literally, other commands can also use dynamic mashup expressions to define the data that should fill this literal structure dynamically.

For example:

Mashup expressions can also contain XPath functions or predicates, such as this example:

These dynamic expression can use XQuery expressions instead of XPath for more complicated construction scenarios such as iterating through several variables or using sorting. See Using XQuery Expressions in Construction Statements.