[texhax] extracting math from pdf file

[Jim Diamond]

On Sun, Dec  5, 2010 at 22:46 (+0100), Benjamin Sambale wrote:

> Dear forum,

> consider the following code:

> \documentclass{minimal}
> \begin{document}
> $\ne$
> \end{document}

> I compiled this code using pdflatex (TeX Live 2010). If I try to copy
> the \ne-symbol in the corresponding pdf-file with the mouse cursor, I
> get an equality-sgin (=) instead. I only tried this with evince as
> pdf viewer, but I suspect that the behavior is similar for other
> viewers. I also tried to use something like

> \pdfglyphtounicode{notequal}{...}

> without success. I'm very grateful for any ideas.

A quick peek in plain.tex shows that, at least there, \ne is an
over-struck combination of two characters:

	\def\neq{\not=} \let\ne=\neq

If LaTeX does the same thing, then there is no single "not equal" glyph.

				Jim