> For the complete documentation index, see [llms.txt](https://nelson-9.gitbook.io/nelson/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nelson-9.gitbook.io/nelson/markdown/en/validators/mustbenonpositive.md).

# mustBeNonpositive

Checks that value is non positive or raise an error.

## 📝 Syntax

* mustBeNonpositive(var)
* mustBeNonpositive(var, argPosition)
* C++: void mustBeNonpositive(const ArrayOfVector& args, int argPosition)

## 📥 Input argument

* var - a variable: all supported types and classes that implement isnumeric, islogical, all, isreal, and le methods.
* argPosition - a positive integer value: Position of input argument.

## 📄 Description

mustBeNonpositive checks that value is non positive or raise an error.

## 💡 Example

```matlab
mustBeNonpositive(-1)
mustBeNonpositive(1)
```

## 🔗 See also

[mustBeNonnegative](/nelson/markdown/en/validators/mustbenonnegative.md).

## 🕔 History

| Version | 📄 Description  |
| ------- | --------------- |
| 1.0.0   | initial version |