but what if i want attr nodes where key is specifically equal
to "F"?  i'm assuming that requires a predicate, but i've tested
several variations and none work.  how do i ask if the string-value
is equal to "F"?

//@key["F"] doesn't work

what do i use here as the predicate?  i'm sure i'll be embarrassed
once it's pointed out to me.

where . is a shortcut for self::node() aka context node.
--
Oleg Tkachenko
Multiconn Technologies, Israel