XSLT 2.0 and XPath 2.0 Programmer's Reference, 4th Edition (813 page)

Processing Instruction Node (XDM)

A
node
in a
tree
representing an XML
processing instruction
.

Promotion (XPath)

The type-checking rules for
function
calling in XPath, and also for arithmetic operators and comparison operators, allow numeric values to be used where a different numeric type is expected. The operation of converting the supplied
number
to the required type (for example, integer to double) is known as promotion. Similarly,
any URI
values can be promoted to
string
values.

QName (XML Namespaces)

A qualified name. It is either a simple name (an
NCName
) or a name preceded by a namespace prefix and a colon. See also
lexical
QName
and
expanded QName
.

Range Variable (XPath)

A
variable
declared in a
for
,
some
, or
every
expression, which is bound to each
item
in a
sequence
in turn; for example, the variable
$i
in
for $i in 1 to 5 return $i*$i
.

Regular Expression (XPath)

A regular expression is a pattern that
strings
may or may not match. Regular expressions can be used in the three functions
matches()
,
replace()
, and
tokenize()
defined in XPath, and in the

instruction
in XSLT. Regular expressions also appear in the pattern
facet
of
simple type
definitions in XML Schema.

Result Tree (XSLT)

The output of a
stylesheet
. A stylesheet defines a transformation from a source tree to a result tree. XSLT 2.0 allows multiple result trees to be created. The final stage of processing is normally to
serialize
the result tree as a stream of characters or bytes; this is controlled by the selected
output method
.

Reverse Axis (XPath)

An
axis
containing a
sequence
of
nodes
that precede the
context node
in
document order
. Within a
predicate
of an axis
step
that uses a reverse axis (for example,
preceding-sibling::x[position() = 1 to 3]
), position numbers count the nodes in reverse
document order
. However, as with any other axis step, the result of the expression is in forwards
document order
. So this
expression
returns the last three
x
nodes before the context node, in document order.