## LaTeX forum ⇒ Math & Science ⇒ Problem with double subscript and accents

Information and discussion about LaTeX's math and science related features (e.g. formulas, graphs).
Posts: 5
Joined: Thu Apr 07, 2011 4:30 pm

### Problem with double subscript and accents

Hi all, i'm new to the forum and this is my first post.

I want to be able to define e.g.: ${\hat{A}_a}_b$

But this returns the compilation error: "! Double Script". Meanwhile I found out that the problem was with the \hat accent. If I remove it, I don't get any error in compiling: ${A_a}_b$, as expected.

The reason why I need this structure is that I want to be able to define, with the \newcommand function, math symbols involving subscripts and superscripts, e.g.:

\newcommand{\Hu}{\hat{H}_{u}^{+}}

and then still be able to call this symbol with additional subscript:

"The first component of the field $\Hu$ is ${\Hu}_1$".

Can somebody tell me what am I doing wrong, or suggest another way to do what I want.

Posts: 5
Joined: Thu Apr 07, 2011 4:30 pm

CDbile
Posts: 19
Joined: Mon Jan 31, 2011 6:48 pm
Hi,
I found a trick :

${\hat{A}{}_a}_b$

Regards,
CDbile

Posts: 5
Joined: Thu Apr 07, 2011 4:30 pm
Thanks for the help.

CDbile wrote:Hi,
I found a trick :

${\hat{A}{}_a}_b$

Regards,