# \underparen

Used to draw a curved mark under an expression, typically for grouping or geometric notation.

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

## Metadata

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

## Syntax

### base

Argument specification: `m`

Used to draw a curved mark under an expression, typically for grouping or geometric notation.

## Examples

```latex
\underparen{x+y}
```

[Open in Playground](https://play.texform.dev/?input=%5Cunderparen%7Bx%2By%7D)

## Renderer support

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

## In TeXForm

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

## See also

- [\\overbrace](https://texform.dev/latex/commands/overbrace)
- [\\overleftarrow](https://texform.dev/latex/commands/overleftarrow)
- [\\overleftrightarrow](https://texform.dev/latex/commands/overleftrightarrow)
- [\\overline](https://texform.dev/latex/commands/overline)
- [\\overparen](https://texform.dev/latex/commands/overparen)
- [\\overrightarrow](https://texform.dev/latex/commands/overrightarrow)
- [\\underbrace](https://texform.dev/latex/commands/underbrace)
- [\\underleftarrow](https://texform.dev/latex/commands/underleftarrow)
- [\\underleftrightarrow](https://texform.dev/latex/commands/underleftrightarrow)
- [\\underline](https://texform.dev/latex/commands/underline)
- [\\underrightarrow](https://texform.dev/latex/commands/underrightarrow)

## Test cases

### base

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \underparen{a} | Positive: baseline | Pass | Fail | Fail |
| \underparen a | Positive: bare[0] | Pass | Fail | Fail |