# E4155

Cycle in `const`, `fnalias`, `typealias` or `traitalias` declaration.

`const` declaration can refer to other constants defined in the same package,
and `fnalias` can alias other function alias in the same package, too.
`typealias` and `traitalias` can also refer to other `typealias`/`traitalias` in current package.
But these definitions must not form cycle, otherwise this error will be reported.

## Erroneous example
```{literalinclude} /sources/error_codes/4155_error/top.mbt
:language: moonbit
```