Chapter 4. XPath functions
| Part II. XPath 1.0 support |

## Chapter 4. XPath functions

All the standard XPath 1.0 functions are supported: `boolean`, `ceiling`, `concat`, `contains`, `count`, `false`, `floor`, `id`, `lang`, `last`, `local-name`, `name`, `namespace-uri`, `normalize-space`, `not`, `number`, `position`, `round`, `starts-with`, `string`, `string-length`, `substring`, `substring-after`, `substring-before`, `sum`, `translate`, `true`.

The following XSLT 1.0 functions are also supported: `current`, `document`, `format-number`, `system-property`, `key`, `generate-id`, `function-available`, `element-available`, `unparsed-entity-uri` with the following specificities:

- In `document(`relative_URI`)`, `relative_URI` is not resolved against the URI of the XSLT stylesheet (because there is no such XSLT stylesheet).

- The 3-argument form of `format-number()` is not supported.

- `key()` always returns an empty node-set when used outside a XED script or a Schematron.

- `element-available()` returns `true` for any element name in the "`http://www.w3.org/1999/XSL/Transform`" namespace and `false` otherwise.

- `unparsed-entity-uri()` always returns an empty string.

- `system-property()` supports the following XSLT 1.0 properties: `xsl:version`, `xsl:vendor`, `xsl:vendor-url`, and also the following XSLT 2.0 properties: `xsl:product-name`, `xsl:product-version`, in addition to Java™'s system properties.

Part II. XPath 1.0 support |  | 1. Extension functions