Variables in DocBook with the XSL stylesheets

Hi List,

when writing something in DocBook today, I found myself using a 
variable in the mathematical sense, i.e. not a program variable. As in 
the sentence "Let n be a natural number.". Using <varname> around the 
'n' typesets it in monospace while in such cases italic would be more 
appropriate. Is there an element other than <varname> for such "natural 
language variables" which I have overlooked or how would I deal with 
this? Changing the stylesheet for <varname> is not an option because I 
also have program variables that I want to keep in monospace.

Thanks in advance,
Sven Moritz