RE: Test For Numeric Values?

> For some background - why does XSLT allow zeros to be treated as
> booleans when it causes these kind of nuances?
> 

XSLT 1.0 was developed in the tradition of scripting languages like
JavaScript that allow very free conversion between data types; and there was
a philosophy of trying to avoid dynamic errors as far as possible, so every
construct had a defined successful outcome. This was related to the fact
that some people expected XSLT to be used mainly in the browser, where
errors are a nightmare to handle.

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