XSLT 1.0 (XPath 1.0) で node-set (というか単一ノード) を = で比較するときってどうなるんだっけ。 string() 的な変換がかかってから比較されるんだっけか
XML Path Language (XPath)
https://www.w3.org/TR/1999/REC-xpath-19991116/#booleans
> If both objects to be compared are node-sets, then the comparison will be true if and only if there is a node in the first node-set and a node in the second node-set such that the result of performing the comparison on the string-values of the two nodes is true.
合ってた