# ams/dbinom-and-tbinom-to-binom

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

https://texform.dev/rules/ams/dbinom-and-tbinom-to-binom

## Metadata

| Field | Value |
| --- | --- |
| Key | ams/dbinom-and-tbinom-to-binom |
| Level | equiv |
| Fidelity | reading |
| Enabled by packages | ams |
| Profiles | Equiv |

## Rewrite patterns

### display-style

From:

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

To:

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

### text-style

From:

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

To:

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

## Examples

Examples show the rule in isolation, not a complete normalization profile.

### dbinom plain

Before:

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

After this rule:

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

Packages: base, ams.

The rendered result has pixel differences from the input.

### dbinom script

Before:

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

After this rule:

```latex
x_{\binom{n}{k}}
```

Packages: base, ams.

The rendered result has pixel differences from the input.

### tbinom plain

Before:

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

After this rule:

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

Packages: base, ams.

The rendered result has pixel differences from the input.

### tbinom display

Before:

```latex
\displaystyle\tbinom{n}{k}
```

After this rule:

```latex
\displaystyle\binom{n}{k}
```

Packages: base, ams.

The rendered result has pixel differences from the input.

### tbinom script

Before:

```latex
x_{\tbinom{n}{k}}
```

After this rule:

```latex
x_{\binom{n}{k}}
```

Packages: base, ams.

The rendered result has pixel differences from the input.

## Triggers

- [\\dbinom](https://texform.dev/latex/commands/dbinom)
- [\\tbinom](https://texform.dev/latex/commands/tbinom)

## Eliminates

- [\\dbinom](https://texform.dev/latex/commands/dbinom)
- [\\tbinom](https://texform.dev/latex/commands/tbinom)

## Produces

- [\\binom](https://texform.dev/latex/commands/binom)

## Same family

- [ams/cfrac-to-frac](https://texform.dev/rules/ams/cfrac-to-frac): Drop continued-fraction styling from centered AMS cfrac forms.
- [ams/dfrac-to-frac](https://texform.dev/rules/ams/dfrac-to-frac): Rewrite the AMS display-style fraction command to frac.
- [ams/tfrac-to-frac](https://texform.dev/rules/ams/tfrac-to-frac): Rewrite the AMS text-style fraction command to frac.
- [base/above-to-genfrac](https://texform.dev/rules/base/above-to-genfrac): Rewrite above to a thickness-preserving genfrac form.
- [base/abovewithdelims-to-genfrac](https://texform.dev/rules/base/abovewithdelims-to-genfrac): Rewrite abovewithdelims to an explicit genfrac with delimiters and thickness.
- [base/atop-to-genfrac](https://texform.dev/rules/base/atop-to-genfrac): Rewrite infix atop to an explicit no-rule genfrac form.
- [base/atopwithdelims-to-genfrac](https://texform.dev/rules/base/atopwithdelims-to-genfrac): Rewrite atopwithdelims to an explicit delimited no-rule genfrac form.
- [base/brace-to-genfrac](https://texform.dev/rules/base/brace-to-genfrac): Rewrite infix brace to an explicit genfrac with brace delimiters.
- [base/brack-to-genfrac](https://texform.dev/rules/base/brack-to-genfrac): Rewrite infix brack to an explicit genfrac with bracket delimiters.
- [base/choose-to-binom](https://texform.dev/rules/base/choose-to-binom): Rewrite infix choose to an explicit binom command.
- [base/over-to-frac](https://texform.dev/rules/base/over-to-frac): Rewrite infix over to an explicit frac command.
- [base/overwithdelims-to-genfrac](https://texform.dev/rules/base/overwithdelims-to-genfrac): Rewrite overwithdelims to an explicit genfrac with delimiters.
- [base/root-of-to-sqrt](https://texform.dev/rules/base/root-of-to-sqrt): Rewrite legacy root-of syntax to bracketed sqrt notation.
- [base/leftroot-drop](https://texform.dev/rules/base/leftroot-drop): Drop the leftroot index-position hint in cleanup-oriented normalization.
- [base/uproot-drop](https://texform.dev/rules/base/uproot-drop): Drop the uproot index-position hint in cleanup-oriented normalization.

## Notes

AMS defines dbinom and tbinom with forced display and text styles while binom inherits context. The binomial family has a different canonical target from fractions and therefore uses a separate rule; the style loss is intentional Reading normalization.

## Disable this rule

```python
TransformEngine(profile="corpus", disable_rules=["ams/dbinom-and-tbinom-to-binom"])
```

```javascript
new TransformEngine({ profile: 'corpus', disableRules: ['ams/dbinom-and-tbinom-to-binom'] })
```

[Open in Playground](https://play.texform.dev/?input=x%2B%5Cdbinom%7Bn%7D%7Bk%7D)