[xslt] xpath queries from shell revisted

[Dan Stromberg <dstromberglists gmail com>]

I'm having a little trouble with some basic XPath queries from shell.

I dug up a small handful of what-seem-like simple examples from http://
www.w3schools.com/xpath/xpath_syntax.asp and fed them into three xpath 
programs (one in C, one in python, one in perl), and got pretty different 
results from the 3, a number of which I believe must be incorrect.

I've summarized what I found at:

http://stromberg.dnsalias.org/~dstromberg/xml/xpath-issues.html

Is it perhaps the case that some XPath processing programs don't do 
complete xpath?  Are there different levels of xpath implementation 
completeness?

Thanks!