declare default element namespace "http://example.com/Namespace";

declare variable $documentElementName := "doc";

element {$documentElementName}

{

    attribute xml:base {"http://example.com/"},

    element anotherElement

    {

        comment {" a comment "},

        processing-instruction target {"data"},

        element anotherElement {()},

        text {"some text"}

    }

}