While Using the command \L in LaTeX
Error Display:
latex error mathcal allowed only in math mode
[Tex/LaTex] How to use the \L command in LaTeX
errorsmath-mode
Related Solutions
Before you load the offending package, put
\let\Horig\H
and then you can say Erd\Horig{o}s
Your problem is:
$p( \bar{E} \cap \bar{F}) = p( \bar{E \cup F})
= 1 - p(E \cup F) = 1 - p(E) - p(F) + p(E \cap F)
= 1 - p(E) - p(F) +
% -------------------
p(E)p(F\) %right here
% -------------------
= (1-p(E))(1-p(F)) = p( \bar{E})p( \bar{F})$
p(E)p(F\). That's your problem. \) exits math mode. \( ... \) is an alternative to $ ... $. Where you've put \), it's exited math mode. And then when you have \bar afterwards, you're outside of math mode, and:
\bar allowed only in math mode
If we correct that, then it compiles, however, \bar{E \cup F} is not going to work out very well, you probably want \overline{E \cup F}
Might I also recommend something more like:
\begin{flalign*}
p(\bar{E} \cap \bar{F}) &= p(\,\overline{E \cup F}\,) \\[\parskip]
&= 1 - p(E \cup F) \\[\parskip]
&= 1 - p(E) - p(F) + p(E \cap F) \\[\parskip]
&= 1 - p(E) - p(F) + p(E)p(F) \\[\parskip]
&= (1-p(E))(1-p(F)) \\[\parskip]
&= p(\bar{E})p(\bar{F})
\end{flalign*}
Best Answer
The standard command
\Lmay not be used in math at all, so will not give the error you show.I would guess that a local definition in your files has
in which case it will generate a curly L in math mode and the error you show if used out of math. To avoid the error use
$\L$to get back to math mode.