# E3019

Inclusive range pattern `a..=b` cannot have `_` as upper bound.

Writing `a..=_` does not make sense, because `_` is a wildcard that matches any
value. It is unclear what does "equals to any value" mean. If you want to
express the meaning of "greater than or equal to `a`", you can use `a..<_`
instead.

## Erroneous example

```{literalinclude} /sources/error_codes/3019_error/top.mbt
:language: moonbit
```

## Suggestion

Replace `..=_` with `..<_`:

```{literalinclude} /sources/error_codes/3019_fixed/top.mbt
:language: moonbit
```