The answers I reached when I asked myself the same questions for Saxon were:

> 1. What should be output from the following stylesheet 
> fragment, assuming
> that "unknown" is not an element in the current stylesheet:
> 
> 	<xsl:number count="unknown" level="any" format="1."/>
> 
The number to be output is zero. The way non-positive numbers are formatted
is not defined by the spec, so I ignore the format attribute and just use
the same conversion as the string() function.

> when level="any" and no matches are
> found, the spec doesn't say an empty list should be returned. 
>  Is this an oversight, or should 0 be returned?

It may be an oversight, but whether intentional or not the rules clearly say
the answer is zero.
> 
> 2. If an empty list should be returned, then should any 
> format tokens (such as the ".") be output?

Again the rules here are clear, the output should be ".".

> 
> 3. How about negative numbers:
> 
> 	<xsl:number value="-1" format = "1."/>
> 
The rules here are undefined, I ignore the format and display the answer
using string().

Mike Kay


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