Following the question "The \bar and \overline commands" which is simply about the lengths of both, I'd like to know when to use `\bar`

and when to use `\overline`

from a semantically viewpoint.

I always used `\bar`

, because up until now I only had single letter mean values to type. But now I came to a problem where I needed a wider "bar".

Then I just tried

```
\documentclass{article}
\begin{document}
\[ \bar{a} \overline{a} \]
\[ \bar{abc} \overline{abc} \]
\end{document}
```

where one can see that they also differ in position (`\overline`

is lower), and also in thickness (`\overline`

is thicker).

So, the question here is:

**What does \bar represent semantically? And when to choose it over \overline and vice versa?**

## Best Answer

Semantically, don't use either. Use`\conj`

, or`\mean`

, or`\variant`

or whatever the overline ismeantto mean. Then in your preamble, do:Then:

sourcebecomes readable: you can determine the meaning right there and then.`\conj`

without worrying about changing what`\mean`

does.`\bar`

to`\overline`

on a whim and don't have to make that crucial decision now.