XSLT 2.0 and XPath 2.0 Programmer's Reference, 4th Edition (427 page)

Both operands to the union, intersect, and except operators must be sequences of zero or more nodes. A type error will occur if this isn't the case. The input sequences don't have to be in any particular order, and they are allowed to contain duplicates; the original order and the duplicates will have no effect on the result.

Examples

Expression

Description

*/figure | */table

Returns a node-set containing all the grandchildren of the context node that are or elements. This can also be written */(figure|table) . book[not(@publisher)] | book[@publisher = ‘Wrox’] Returns all the children of the context node that either have no publisher attribute or that have a publisher attribute equal to “Wrox”. Note that the same result could be achieved, perhaps more efficiently, by using the or operator in the predicate. (.|..)/title Returns all the