# S06004 {#s06004}

## Error Code {#error_code .section}

S06004

## Error Message {#error_message .section}

`The function or procedure <xxx> is not defined. RefId: S06004`

## Probable Causes {#probable_causes .section}

The format of a function's fully qualified name is:

``` {#codeblock_ryx_h2t_1bc}
moduleName :: functionName
```

If the module name is empty, it refers to the global namespace.

For example, if the function `f` does not exist in the `mod` namespace, this error is reported.

``` {#codeblock_ojd_j2t_1bc}
mod::f()
```

## Solutions {#solutions .section}

Check if the function is defined in the specified namespace.

**Parent topic:**[Error Code Reference](../../Troubleshooting/ErrorCode.md)

