Re: Distinguishing the root node of a node-set

you want 
test="$var/self::root1"
but that isn't what you asked for, a root node in XPath is never an
element node with a name, it is the node denoted by / that is the parent
of the top level element. Xpath2 calls these nodes document nodes rather
than root nodes to try to avoid  this confusion over the term "root"

David