# Function not Logical `not`. Flips boolean value of a given parameter. For matrices, the function is evaluated element wise. ## Syntax ```js math.not(x) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `x` | number | BigNumber | Complex | Unit | Array | Matrix | First value to check ### Returns Type | Description ---- | ----------- boolean | Array | Matrix | Returns true when input is a zero or empty value. ## Examples ```js math.not(2) // returns false math.not(0) // returns true math.not(true) // returns false a = [2, -7, 0] math.not(a) // returns [false, false, true] ``` ## See also [and](and.md), [or](or.md), [xor](xor.md)