trueif the previous element is the specified element, and
isntreverses the result.
previous element-qualifier? (is | isnt) namespace-modifier? (element-name | element-name-list)
previous is tests whether the previous sibling of the current element of the currently-active parse is
an instance of the element element-name, or one of the elements listed in element-name-list.
element-name-list is a parenthesized list of elements, separated by
isnt will reverse these results.
If element-qualifier is not specified, the test applies to the previous sibling element of the current element. If element-qualifier is specified, the test applies to the previous sibling element of the element specified by element-qualifier.
You can specify the name dynamically by using the identity operator (
~) followed by a
string expression: for example, to check for elements with a previous sibling element of the same name as
the current element,
previous is test ignores inclusions and data content.