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# assumptions

Show assumptions set on symbolic variable

## Description

example

assumptions(var) returns all assumptions set on variable var.

example

assumptions returns all assumptions set on all variables in MATLAB® Workspace.

## Examples

### Assumptions on Several Variables

Show the assumptions set on variables n and x separately, and then show assumptions set on all variables.

Assume that the variable n is integer and the variable x is rational. In addition to that , assume that the product n*x belongs to the interval from -100 to 100:

```syms n x
assume(n,'integer')
assume(x,'rational')
assumeAlso(-100 <= n*x <= 100)
```

To see the assumptions set on the variable n, enter:

`assumptions(n)`
```ans =
[ -100 <= n*x, n*x <= 100, n in Z_]```

To see the assumptions set on the variable x, enter:

`assumptions(x)`
```ans =
[ -100 <= n*x, n*x <= 100, x in Q_]```

To see the assumptions set on all variables, use assumptions without any arguments:

`assumptions`
```ans =
[ -100 <= n*x, n*x <= 100, n in Z_, x in Q_]```

For further computations, clear the assumptions:

`syms n x clear`

### Multiple Assumptions on One Variable

Show the assumptions set by using syms and assume.

Use assumptions to return all assumptions, including those set by the syms command:

```syms x real
assumeAlso(x < 0)
assumptions(x)```
```ans =
[ x < 0, x in R_]```

## Input Arguments

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### var — Variable for which to show assumptionssymbolic variable | array of symbolic variables | vector of symbolic variables | matrix of symbolic variables

Variable for which to show assumptions, specified as a symbolic variable or array, vector, or matrix of symbolic variables.

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### Tips

• When you delete a symbolic object from the MATLAB workspace by using clear, all assumptions that you set on that object remain in the symbolic engine. If later you declare a new symbolic variable with the same name, it inherits these assumptions.

• To clear all assumptions set on a symbolic variable var and the value of the variable, use this command:

` syms var clear`
• To clear assumptions and keep the value of the variable, use this command:

`sym('var','clear')`
• To clear all objects in the MATLAB workspace and close the MuPAD® engine associated with the MATLAB workspace resetting all its assumptions, use this command:

`clear all`