bug#26125: ispell fails to detect certain typos

[Leon Meier]

> 1) Try $\sigma$ contradition -- it has the same effect within LaTeX
Then ispell complains, which is its correct behavior.

> 2) Try \( \sigma \) contradition -- note the spaces around \sigma; same
> effect, but ugly
Then ispell also complains, which is also its correct behavior.

> 3) Eval the form in verbatim environment below and run ispell again:
>
> --8<---------------cut here---------------start------------->8---
> \documentclass{article}
>
> \begin{document}
>
> \begin{verbatim}
> (TeX-ispell-skip-setcar
>   '(("\\\\(" . "\\\\)")))
> \end{verbatim}
>
> \(\sigma\) contradition
>
> $\sigma$ contradition
>
> \end{document}
> --8<---------------cut here---------------end--------------->8---
I'm not quite sure what you mean. I did
M-x eval-expression <RET>
and pasted
(TeX-ispell-skip-setcar '(("\\\\(" . "\\\\)")))
into the minibuffer.
After that, ispell complained correctly.

> If it works, I can add it to tex-ispell.el.
>
> 4) Disable the new feature by setting `TeX-ispell-extend-skip-list' to
> nil.
After appending

(setq TeX-ispell-extend-skip-list nil)

to .emacs , ispell complained correctly.

Thank you, that helped.

The options 1) and 2) are out of question in the long run for legacy 
latex code with \( and \) you wouldn't like to change. I wouldn't like 
to run eval-expression each time I start emacs, so 3) is out of question 
for me now. I guess, 4) could be a current workaround for me.

Note that if you replace \sigma by x (or some other Latin letter), 
ispell also complains correctly, so, per se, \( \) poses a problem only 
under certain special circumstances.

Best,
Leon

> HTH.
>
> Best, Arash