xpath - how to find a node where a specific attribute does NOT exist?

[KathyB]

Hi, since there doesn't appear to be a way to get the individual
elements that make up the xpath to a result node, I'm trying to create
an xpath that will result in selecting this xml node which would be
the last board element without a finish attribute.

<Board sn@="12347" start="7/15/03"/>

other board elements may include a finish attribute, e.g,
<Board sn@="12346" start="7/15/03" finish="7/15/03"/>

if I try to include a predicate of [@finish = ""] it doesn't select
the node.

How do you select a node that does NOT have a certain attribute?

Thanks!

Kathy