Union of two XSL

Good morning experts,
today also, i need of your help :-)... I hope that you can help me about a
doubt. Well, i would like to know if with XML:FO is possible to take two
different XSL and put all into a PDF document only.
For example i have two XML and two XSL structures: XMLFile1.xml,
XMLFile2.xml, XSLFile1.xsl, XSLFile2.xsl. I would like create a PDF Document
only for the two structure XSL. Someone can tell me if it is possibile with
FO?
Thank you and regards...
    Gianni