# Type::NegInt

Type and property representing negative integers

### Use only in the MuPAD Notebook Interface.

This functionality does not run in MATLAB.

## Syntax

```testtype(`obj`, Type::NegInt)
assume(`x`, Type::NegInt)
is(`ex`, Type::NegInt)
```

## Description

`Type::NegInt` represents negative integers. `Type::NegInt` is a property, too, which can be used in an `assume` call.

The call `testtype(obj, Type::NegInt)` checks, whether `obj` is a negative integer number and returns `TRUE`, if it holds, otherwise `FALSE`.

`testtype` only performs a syntactical test identifying MuPAD® objects of type `DOM_INT` and checks, if `bool(obj < 0)` holds.

The call `assume(x, Type::NegInt)` marks the identifier `x` as a negative integer number.

The call `is(ex, Type::NegInt)` derives, whether the expression `ex` is a negative integer number (or this property can be derived).

This type represents a property that can be used in `assume` and `is`.

## Examples

### Example 1

The following numbers are of type `Type::NegInt`:

```testtype(-2, Type::NegInt), testtype(-3, Type::NegInt), testtype(-55, Type::NegInt), testtype(-1, Type::NegInt), testtype(-111111111, Type::NegInt)```

### Example 2

Assume an identifier is a negative integer:

```assume(x, Type::NegInt): is(x, Type::NegInt)```

Negative integers are integers, of course:

```assume(x, Type::NegInt): is(x, Type::Integer)```

However, integers can be negative or not:

```assume(x, Type::Integer): is(x, Type::NegInt)```

`delete x:`

## Parameters

 `obj` Any MuPAD object `x` An identifier or a mathematical expression containing identifiers `ex`