Returns the sign of the argument.

The `sign`

function, which is also called signum, returns the sign of * z*.

`z`

`z`

`z`

`z`

`z`

`z`

The unit step function.

u(z) is commonly known as the unit step function.
* z* may be any

`z`

`z`

`z`

Finds and returns the minimum of the values passed as arguments.

The `min`

function returns the minimum value of its arguments.
`min`

can take any number of arguments not less than 2.
The arguments may be any *numeric expressions*
that evaluate to *real numbers* or *complex numbers*.
If the arguments are complex numbers, the function returns min(re(A), re(B), ...) + min(im(A), im(B), ...)**i**.

Finds and returns the maximum of the values passed as arguments.

The `max`

function returns the maximum value of its arguments.
`max`

can take any number of arguments not less than 2.
The arguments may be any *numeric expressions*
that evaluate to *real numbers* or *complex numbers*.
If the arguments are complex numbers, the function returns max(re(A), re(B), ...) + max(im(A), im(B), ...)**i**.

Returns the second argument if it is in the range between the first argument and the third argument.

The `range`

function returns * z*,
if

`z`

`A`

`B`

`z`

`A`

`A`

`z`

`B`

`B`

Evaluates one or more conditions and returns a different result based on them.

The `if`

function evaluates * cond1* and if it is different from 0 then

`f1`

`cond2`

`f2`

`fz`

`fz`

`if`

returns an error if none of the conditions are true.
The arguments may be any