------
## 最终结论
```python
def unique(l: list):
    """Return sorted unique elements in a list
    >>> unique([5, 3, 5, 2, 3, 3, 9, 0, 123])
    [0, 2, 3, 5, 9, 123]
    """
    unique_elements = set(l)
    sorted_unique_elements = sorted(unique_elements)
    return sorted_unique_elements
```