# Documentation

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# `Type`::`NegRat`

Type and property representing negative rational numbers

MATLAB live scripts support most MuPAD functionality, though there are some differences. For more information, see Convert MuPAD Notebooks to MATLAB Live Scripts.

## Syntax

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

## Description

`Type::NegRat` represents negative rational numbers. `Type::NegRat` is a property, too, which can be used in an `assume` call.

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

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

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

The call `is(ex, Type::NegRat)` derives, whether the expression `ex` is a negative rational 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::NegRat`:

```testtype(-2, Type::NegRat), testtype(-3/4, Type::NegRat), testtype(-55/111, Type::NegRat), testtype(-1, Type::NegRat), testtype(-111/111111, Type::NegRat)```

### Example 2

Assume an identifier is negative rational:

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

Also negative rational numbers are rational:

```assume(x, Type::NegRat): is(x, Type::Rational)```

However, rational numbers can be negative rational or not:

```assume(x, Type::Rational): is(x, Type::NegRat)```

`delete x:`

## Parameters

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