# E4017

Method of type is ambiguous, it may come from multiple traits.

## Erroneous Example

```{literalinclude} /sources/error_codes/4017_error/top.mbt
:language: moonbit
```

The example above tries to call the method `value` on a type `S`,
but the method name comes from both `A` and `B` traits,
giving an error like:

```
Method value of type S is ambiguous, it may come from trait A or B
```

## Suggestion

Disambiguate the method by specifying the trait it comes from:

```{literalinclude} /sources/error_codes/4017_fixed/top.mbt
:language: moonbit
```