I want to type the below formula.
When I type I get an error saying Double subscript
The code I wrote for this formula
\left \{ e_{ij}^{l} \right \}_{i,j}_{\in \omega _{l}}
[Tex/LaTex] Double subscript error
equationssubscripts
Related Solutions
This works so long as you put always subscripts next to the newly defined commands:
\documentclass[a4paper]{article}
\makeatletter
\newcommand\newsubcommand[3]{\newcommand#1{#2\sc@sub{#3}}}
\def\sc@sub#1{\def\sc@thesub{#1}\@ifnextchar_{\sc@mergesubs}{_{\sc@thesub}}}
\def\sc@mergesubs_#1{_{\sc@thesub#1}}
\makeatother
\newsubcommand{\xa}{x}{a}
\begin{document}
$\xa$
$\xa_i x_{ai}\xa^2 x_a^2$
\end{document}
It might be extended to support \xa^2_i, but it doesn't seem a good idea to add complications.
Explanation
The command \newsubcommand defines an abbreviation where the first argument is the command to define, the second is the main letter and the third is the fixed subscript.
The macro \xa defined in the example will look whether the following character is _ and, if so, it will merge the subscripts.
The error is caused by the improper double subscript h_{j)}_0 (of type a_b_c). Add brackets to help latex discriminate between a_{b_c} or {a_b}_c.
Note that is similar to the ambiguity in maths: is 2^3^4 supposed to mean 8^4 or 2^81?
Best Answer
It must be either
for a real double (in fact a triple) subscript or
if everything should be in a single subscript line, which is what you want to achieve, I guess ...