# Left/Right
Delimiter matching.
The `lr` function allows you to match two delimiters and scale them with the
content they contain. While this also happens automatically for delimiters
that match syntactically, `lr` allows you to match two arbitrary delimiters
and control their size exactly. Apart from the `lr` function, Typst provides
a few more functions that create delimiter pairings for absolute, ceiled,
and floored values as well as norms.
To prevent a delimiter from being matched by Typst, and thus auto-scaled,
escape it with a backslash. To instead disable auto-scaling completely, use
`{set math.lr(size: 1em)}`.
# Example
```example
$ [a, b/2] $
$ lr(]sum_(x=1)^n], size: #50%) x $
$ abs((x + y) / 2) $
$ \{ (x / y) \} $
#set math.lr(size: 1em)
$ { (a / b), a, b in (0; 1/2] } $
```
## Functions
### `lr`
Scales delimiters.
While matched delimiters scale by default, this can be used to scale
unmatched delimiters and to control the delimiter scaling more precisely.
### `mid`
Scales delimiters vertically to the nearest surrounding `{lr()}` group.
### `abs`
Takes the absolute value of an expression.
### `norm`
Takes the norm of an expression.
### `floor`
Floors an expression.
### `ceil`
Ceils an expression.
### `round`
Rounds an expression.