> My problem is that I can't include/import B and C within A 
> because each uses an fxsl library and, since that library 
> contains includes, I get a parse error that doesn't like the 
> fact that two sheets are including the same file without 
> import preference.

Not a problem if there's an import somewhere in the structure. E.g. if A
imports B or C or both, or if either or both of B and C imports FXSL.

Michael Kay
http://www.saxonica.com/