# contains

### Description

`contains` is used to check a list of values, which is given on the left of the operator, against a single value on the right.

### Example

A person can have multiple nationalities. If you want to include US tax documents if one of those nationalities is the United States, you could attach this condition to those [documents](https://docs.atfinity.io/guides/glossary/document):

```
p is Person
p.nationalities contains us
```

The list of nationalities of the person in this case should include `us` , meaning this condition evaluates to true and the documents to which it is attached will be included in the [case](https://docs.atfinity.io/guides/glossary/case).