# E4083

The default value in a `with` pattern cannot refer to a binder introduced by
the complete pattern. The default expression is evaluated in the surrounding
scope, where that binder is not available.

## Erroneous example

```{literalinclude} /sources/error_codes/4083_error/top.mbt
:language: moonbit
```

## Suggestion

Use a value that is available in the surrounding scope.

```{literalinclude} /sources/error_codes/4083_fixed/top.mbt
:language: moonbit
```