> For the complete documentation index, see [llms.txt](https://docs.atfinity.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.atfinity.io/rule-language/operators/list-operators/set_difference.md).

# SET\_DIFFERENCE

### Description

The SET\_DIFFERENCE function removes the elements of the right set from the left set. You can also use the infix operator - to achieve the same.

### Example

```
p is Person
COUNT(
    SET_DIFFERENCE(p.countries_with_citizenships, FORBIDDEN_COUNTRIES)
) > 0
```

The set of citizens a person has is shortened by a list of forbidden countries. If the person is a citizen of any remaining countries, true is returned.

Using the infix operator, the same example would look like

```
p is Person
COUNT(
    p.countries_with_citizenships - FORBIDDEN_COUNTRIES
) > 0
```


---

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