# physics/probability-to-pr

Collapse a bare Probability helper to the standard Pr operator.

https://texform.dev/rules/physics/probability-to-pr

## Metadata

| Field | Value |
| --- | --- |
| Key | physics/probability-to-pr |
| Level | authoring |
| Fidelity | render |
| Enabled by packages | physics |
| Profiles | Authoring, Faithful, Corpus, Equiv |

## Rewrite patterns

### bare

From:

```latex
\Probability
```

To:

```latex
\Pr
```

## Examples

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

### Probability event

Before:

```latex
\Probability A=\frac{1}{2}
```

After this rule:

```latex
\Pr A=\frac{1}{2}
```

Packages: base, physics.

Rendering verified with the declared packages.

## Triggers

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

## Produces

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

## Touches

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

## Downstream

- [physics/physics-operator-fence-expand](https://texform.dev/rules/physics/physics-operator-fence-expand): Expand the physics auto-sized argument of exp, det, and Pr into an explicit fence.

## Same family

- [ams/operatorname-to-named-function](https://texform.dev/rules/ams/operatorname-to-named-function): Rewrite plain operatorname arguments to equivalent base named-function or named-operator commands.
- [ams/idotsint-expand](https://texform.dev/rules/ams/idotsint-expand): Expand idotsint to explicit repeated integral surfaces.
- [base/limits-drop](https://texform.dev/rules/base/limits-drop): Drop explicit limits from an audited operator while preserving attached scripts.
- [base/nolimits-drop](https://texform.dev/rules/base/nolimits-drop): Drop explicit nolimits from an audited operator while preserving attached scripts.
- [physics/cosine-to-cos](https://texform.dev/rules/physics/cosine-to-cos): Collapse a bare cosine helper to the standard cos operator.
- [physics/naturallogarithm-to-ln](https://texform.dev/rules/physics/naturallogarithm-to-ln): Collapse a bare natural logarithm helper to the standard ln operator.
- [physics/sine-to-sin](https://texform.dev/rules/physics/sine-to-sin): Collapse a bare sine helper to the standard sin operator.
- [physics/trace-capital-to-Tr](https://texform.dev/rules/physics/trace-capital-to-Tr): Collapse a bare Trace with no following argument group to the local Tr anchor.
- [physics/trace-to-tr](https://texform.dev/rules/physics/trace-to-tr): Collapse a bare trace with no following argument group to the local tr anchor.
- [physics/named-fn-paren-expand](https://texform.dev/rules/physics/named-fn-paren-expand): Expand physics power and auto-sized parenthesis arguments of standard named functions.
- [physics/named-fn-to-operatorname](https://texform.dev/rules/physics/named-fn-to-operatorname): Rewrite physics-only named functions to operatorname and expand their auto-sized arguments.
- [physics/physics-operator-fence-expand](https://texform.dev/rules/physics/physics-operator-fence-expand): Expand the physics auto-sized argument of exp, det, and Pr into an explicit fence.
- [physics/rank-to-operatorname-rank](https://texform.dev/rules/physics/rank-to-operatorname-rank): Rewrite rank to an explicit operatorname form instead of a package-local alias.

## Notes

In LaTeX physics.sty 1.3, \Probability is the original \Pr saved with \let, a plain operator that grabs nothing, while the redefined \Pr grabs a following {...}, [...], or (...) argument as an auto-sized fence. The rule renames only a bare \Probability, one not followed by (, [, or a brace group; a \Probability that carries scripts is bare. The renamed command gets the empty argument slots of the active \Pr record. In faithful, named-fn-to-operatorname rewrites the skipped branches to \operatorname{Pr} and keeps the delimiters literal. Touches-only convergence: every Applied removes one bare \Probability; non-matching nodes return Skipped. The produced command and canonical reference use the physics record, which overrides the base definition whenever this rule is enabled.

## Disable this rule

```python
TransformEngine(profile="corpus", disable_rules=["physics/probability-to-pr"])
```

```javascript
new TransformEngine({ profile: 'corpus', disableRules: ['physics/probability-to-pr'] })
```

[Open in Playground](https://play.texform.dev/?input=%5CProbability+A%3D%5Cfrac%7B1%7D%7B2%7D)