# \not

Used to negate relation and operator symbols by overlaying a slash, e.g., \\not= produces ≠, \\not\\in produces ∉

https://texform.dev/latex/commands/not

## Metadata

| Field | Value |
| --- | --- |
| Topic | [Negated relations](https://texform.dev/latex/topics/negated-relations) |
| Packages | base |
| Allowed mode | math |
| Tags |  |
| Commonality | medium |
| Kind | prefix |

## Syntax

### base

Argument specification: ``

Used to negate relation and operator symbols by overlaying a slash, e.g., \\not= produces ≠, \\not\\in produces ∉

## Examples

```latex
\not =
```

[Open in Playground](https://play.texform.dev/?input=%5Cnot+%3D)

```latex
\not \in
```

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

```latex
\not a
```

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

## Renderer support

| Package | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- |
| base | full | full | full |

## Usage frequency

0.26% of formulas in the measured corpus contain this entry, rank 82 of 263 entries with frequency data.

## In TeXForm

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

### [base/not-equals-to-neq](https://texform.dev/rules/base/not-equals-to-neq)

Rewrite \not followed by an equals sign to the canonical \neq character.

Level: authoring. Fidelity: render.

```latex
\not=
```

→

```latex
\neq
```

```latex
a\not=b
```

→

```latex
a\neq b
```

### [base/not-exists-to-nexists](https://texform.dev/rules/base/not-exists-to-nexists)

Rewrite \not\exists to the canonical AMS \nexists character when the target is available.

Level: authoring. Fidelity: render.

```latex
\not\exists
```

→

```latex
\nexists
```

```latex
\not\exists x
```

→

```latex
\nexists x
```

### [base/not-in-to-notin](https://texform.dev/rules/base/not-in-to-notin)

Rewrite \not\in to the canonical \notin character.

Level: authoring. Fidelity: render.

```latex
\not\in
```

→

```latex
\notin
```

```latex
x\not\in A
```

→

```latex
x\notin A
```

### [base/not-right-arrow-to-nrightarrow](https://texform.dev/rules/base/not-right-arrow-to-nrightarrow)

Rewrite not followed by a U+2192 right arrow to the canonical AMS nrightarrow character.

Level: authoring. Fidelity: render.

```latex
\not\to
```

→

```latex
\nrightarrow
```

```latex
a\not\to b
```

→

```latex
a\nrightarrow b
```

## Test cases

### base

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \not | Positive: baseline | Pass | Pass | Pass |