I'd like my axis to be labeled $s(t)=\delta(t)$, but this does not work because of the = sign (key-value separator). I had a look into the "Comprehensive Symbols Guide" referenced here: http://w2.syronex.com/jmr/tex/texsym.old.html I also found \equal, but it seems like another package is used and to avoid that .... does anyone know how to handle that?

For comepleteness, this is what I need to compile.

% \begin{axis}[ylabel=$u_1(t)=\delta(t)$,ymax=1.2] does not work
\begin{axis}[ylabel=$u_1(t)\ne\delta(t)$,ymax=1.2] % different symbol, of course
(0, 0)
(0, 1)
};
\end{axis}

-
What about to protect the equal sign with braces {=}? –  Sigur Aug 20 '12 at 11:23
@Sigur: Yes, that's the right thing to do. Same thing is true if the titles contain commas. Equal signs and commas are parsed by the key-value system, so they need to be grouped using braces to protect them. Would you mind writing an answer? –  Jake Aug 20 '12 at 11:25
@wal-o-mat: You should always post complete minimal example documents instead of code snippets. That saves others the work of having to fill in the missing bits. –  Jake Aug 20 '12 at 11:26

ylabel={$u_1(t)=\delta(t)$}