# One of set

{% hint style="warning" %}
The feature is available for [paid TestMace subscribers](https://testmace.com/pricing/) only.
{% endhint %}

The **One of set assertion** interface is as follows:

![](/files/-M4OJnBF8LwjQ12YgXnK)

This assertion type is used to ensure if the current value equals to one value from the specified set. In the `Expected value type` field you should specify the type of values you want to compare (strings, numbers or JSON objects).

In the `Expected value` field you should set a list of pissible expected values

The `Use negative statement` flag is used for getting the opposite result, i.e. the current value shouldn't exist in the specified set.

### Error Fixing

The error fixing algorithm depends on the `Use negative statement` flag's state:

* false - the current value is added to the list
* true - the current value is removed from the list


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.testmace.com/node-types/assertion-node/one-of-set.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.