XForms CR - 3.2.3 "First-node Rule" Ambiguity

In 3.2.3 a "First-node rule" is expressed in relation to a node-set.

Since, according to XPath 1.0, a node-set is an *unordered* set of nodes the 
rule as currently written is ambiguous/meaningless.

I assume that adding "in document order" to the rule might both remove the 
ambiguity and meet the WG's intent.

Andrew Watt