I use a Swedish usepackage and when I write, for instance, `å`

in formulas I get an error message `please use \mathaccent …`

.

Here's what I try to write:

```
\begin{align}
\begin{split}
{R} = \{alla\:tal\:på\:tallinjen\}
\end{split}
\end{align}
```

At `\end{align}`

I get the error message:

```
Please use \mathaccents for accents in math mode. \add@accent … spacefactor \spacefactor}\accent #1 #2\egroup \spacefactor …
1.54 \end{align}
I'm changing \accent to \mathaccent here: wish me luck.
(Accents are not the same in formulas as in text.)
```

I have tried with `\aa`

but that doesn't work. Where is my failure?

## Best Answer

"Accents" in math mode can have a precise mathematical meaning. For instance

`$\dot{a}$`

isn't related to the use of the letter`ȧ`

in words, but usually means a derivative with respect to time. Similarly,`$\ddot{a}$`

is the second derivative and has nothing to do with`ä`

.Thus TeX disallows text accent commands in math mode: one should know what he/she is writing.

Your case is different: you want

textinside a math formula; then use`\text`

, which is provided by`amsmath`

(you already load it).By the way,

thatformula is unnecessarily complicated:not only is simpler, but provides for better vertical spacing.