When mixing DOM operators with String operators in a single query, parentheses must be used for DOM operations, which is called a group. The result of a group can’t be used for further DOM operations, thus it can be only used in String operations.

For example, a valid query can be:

({{XPATH://div[@class="content"]}} - {{XPATH://h1}}) & {{LITERAL:<p>Copyright 2015-2016</p>}}

The next query is invalid:

({{XPATH://div[@class="content"]}} - {{XPATH://h1}}) + {{XPATH://div[@class="footnote"]}}