Saxon Documentation

Full Contents

About Saxon

Changes in this Release

Notices

Using XSLT 2.0

Using XQuery

Handling Source Documents

XML Schema Processing

XPath API for Java

Saxon on .NET

Extensibility

Saxon Extensions

Sample Saxon Applications

The Saxon SQL Extension

XSLT Elements

XPath 2.0 Expression Syntax
	Introduction
	Constants
	Variable References
	Function Calls
	Axis steps
	Parentheses and operator precedence
	Filter expressions
	Path expressions
	Cast as, Treat as
	Set difference and intersection
»	Union
	Arithmetic expressions
	Range expressions
	Comparisons
	Instance of and Castable as
	Conditional Expressions
	Quantified Expressions
	For Expressions
	Boolean expressions: AND and OR
	Sequence expressions

Function Library

Standards Conformance

Union

The | operator was available in XPath 1.0; the keyword union has been added in XPath 2.0 as a synonym, because it is familiar to SQL users.

The expression E1 union E2 selects all nodes that are in either E1 or E2 or both. Both expressions must return sequences of nodes. The results are returned in document order. For example, /book/(chapter | appendix)/sections returns all section elements within a chapter or appendix of the selected book element.