Re: regexp problems the evil \[

[Stefan Monnier]

>   (query-replace "\\[" "\\begin{displaymath}\n" nil)
     ^^^^^^^^^^^^^^^^^^^
     matches \[

>   (query-replace-regexp "\\[\\([^}]+\\)\\]" "@\\1" nil))
     ^^^^^^^^^^^^^^^^^^^^^^^^^
        matches [

Since [ in regexps has otherwise a special meaning.
To match \[ and \] you'll want

   (query-replace-regexp "\\\\\\[\\([^}]+\\)\\\\\\]" "@\\1" nil))


-- Stefan