> Okay, here's the deal: I have several XSL stylesheets that do 
> different things [obviously] but use a couple of templates that are 
> common to more than one stylesheet and are thus kept in separate 
> "include" files. The choice of additional template to be included 
> depends on a few other factors that have to do with the specificities 
> of my system, and that would take a long time to explain but probably 
> wouldn't add much to this discussion.

This is in fact the most common reason people ask for this facility. The
answer is to turn the stylesheet structure upside down: instead of having
stylesheet A try to conditionally include B or C, make B and C both include
(or import) A, and then invoke the transformation on B or C depending on the
circumstances.

Michael Kay