| SAXONICA | 
The xsl:include element is always used at the top level of the stylesheet. It has a
            mandatory href attribute, which is a URL (absolute or relative) of another stylesheet
            to be textually included within this one. The top-level elements of the included stylesheet
            effectively replace the xsl:include element.
         
xsl:include may also be used at the top level of the included stylesheet, and so
            on recursively.