# \dbinom

Display-style binomial coefficients forced in tighter contexts when a larger binomial layout is preferred.

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

## Metadata

| Field | Value |
| --- | --- |
| Topic | [Fractions and roots](https://texform.dev/latex/topics/fractions-roots) |
| Packages | ams |
| Allowed mode | math |
| Tags |  |
| Commonality | low |
| Kind | prefix |

## Syntax

### ams

Argument specification: `m m`

Display-style binomial coefficients forced in tighter contexts when a larger binomial layout is preferred.

## Examples

```latex
\dbinom{n}{k}
```

[Open in Playground](https://play.texform.dev/?input=%5Cdbinom%7Bn%7D%7Bk%7D)

## Renderer support

| Package | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- |
| ams | full | full | full |

## Usage frequency

<0.01% of formulas in the measured corpus contain this entry, rank 181 of 263 entries with frequency data.

## In TeXForm

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

### [ams/dbinom-and-tbinom-to-binom](https://texform.dev/rules/ams/dbinom-and-tbinom-to-binom)

Rewrite AMS display-style and text-style binomial commands to binom.

Level: equiv. Fidelity: reading.

```latex
\dbinom{#1}{#2}
```

→

```latex
\binom{#1}{#2}
```

```latex
x+\dbinom{n}{k}
```

→

```latex
x+\binom{n}{k}
```

## Equivalent forms

```latex
\genfrac{(}{)}{0}{0}{#1}{#2}
```

exact. This AMS mapping fixes \genfrac to use ( and ) delimiters, linethickness 0, and style 0.

```latex
{\displaystyle \binom{x}{y}}
```

exact. 

## See also

- [\\binom](https://texform.dev/latex/commands/binom)
- [\\dfrac](https://texform.dev/latex/commands/dfrac)
- [\\frac](https://texform.dev/latex/commands/frac)
- [\\genfrac](https://texform.dev/latex/commands/genfrac)
- [\\tbinom](https://texform.dev/latex/commands/tbinom)
- [\\tfrac](https://texform.dev/latex/commands/tfrac)

## Test cases

### ams

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