This section shows you how the named regular expression classes may be used, for example, to match standard mathematical expressions, like
2 + 3 * (7 - 9) or 2 + 3 * 8 - 11. First, we need to define a number of regular expression classes:
group \((?$expr)\) factor \d+|(?$group) term (?$factor)( \* (?$factor)| / (?$factor))* expr (?$term)( \+ (?$term)| - (?$term))*
Now, if you execute the Find All command in regular expression mode and enter the
as regular expression to search for, all mathematical expressions in the document get selected.