# \overunderset

Places simultaneous over- and under-annotations on a base expression, e.g. labeling a symbol with text or arrows above and below it.

https://texform.dev/latex/commands/overunderset

## Metadata

| Field | Value |
| --- | --- |
| Topic | [Accents](https://texform.dev/latex/topics/accents) |
| Packages | base |
| Allowed mode | math |
| Tags |  |
| Commonality | low |
| Kind | prefix |

## Syntax

### base

Argument specification: `m m m`

Places simultaneous over- and under-annotations on a base expression, e.g. labeling a symbol with text or arrows above and below it.

## Examples

```latex
\overunderset{a}{b}{c}
```

[Open in Playground](https://play.texform.dev/?input=%5Coverunderset%7Ba%7D%7Bb%7D%7Bc%7D)

```latex
\overunderset abc
```

[Open in Playground](https://play.texform.dev/?input=%5Coverunderset+abc)

## Renderer support

| Package | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- |
| base | full | none | none |

## Usage frequency

<0.01% of formulas in the measured corpus contain this entry, rank 254 of 263 entries with frequency data.

## In TeXForm

TeXForm parses this entry as prefix syntax; the package determines its argument specification.

## Equivalent forms

```latex
\overset{#1}{\underset{#2}{#3}}
```

approximate. Often visually similar for simple inputs, but MathJax parses this command as a single munderover node while the nested form produces nested mover/munder structure.

```latex
\mathop{#3}\limits_{#2}^{#1}
```

approximate. Close when the base should behave like an operator with limits; this form forces operator semantics and can differ in spacing/classification from \overunderset.

## Test cases

### base

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \overunderset{a}{b}{c} | Positive: baseline | Pass | Fail | Fail |
| \overunderset a{b}{c} | Positive: bare[0] | Pass | Fail | Fail |
| \overunderset{a}b{c} | Positive: bare[1] | Pass | Fail | Fail |
| \overunderset{a}{b}c | Positive: bare[2] | Pass | Fail | Fail |