Identifying patterns within texts

Well I am 4 days into understanding XSLT (and well 4 days into fully
understanding xml).  I am working on a file conversion utility where it
would be an xml to xml conversion.  In my research, I came across XSLT
(along with XSL, XSL-FO,  XSD, DTD, etc).  My question is the following,
if I have an element with text in it:



                        <item>What is 1/2 in decimal format?</item>





Is there a way using a style sheet to actually manipulate the text such
that the resulting output would be:

              < question>What is <math>1/2</math> in decimal
format</item>



Basically, I need to search through the text of an element and attempt
to detect math?  Most of the tutorials use xml to HTML as an example and
play with elements and attributes.  I was just wandering if the XSLT
spec allows for this type of searching/parsing?



Thanks,

Jim Themis