# math

## `(dec! x)`

Macro defined at lib/math/init.lisp:83:2

Decrements the symbol `X` by 1.

### Example

``````> (with (x 1)
.   (dec! x)
.   x)
out = 0
``````

## `(even? x)`

Defined at lib/math/init.lisp:27:2

Is `X` an even number?

### Example

``````> (even? 2)
out = true
> (even? 1)
out = false
``````

## `(gcd x y)`

Defined at lib/math/init.lisp:3:2

Compute the greatest common divisor of `X` and `Y`.

### Example

``````> (gcd 52 32)
out = 4
``````

## `(inc! x)`

Macro defined at lib/math/init.lisp:71:2

Increments the symbol `X` by 1.

### Example

``````> (with (x 1)
.   (inc! x)
.   x)
out = 2
``````

## `(lcm x y)`

Defined at lib/math/init.lisp:16:2

Compute the lowest common multiple of `X` and `Y`.

### Example

``````> (lcm 52 32)
out = 416
``````

## `(nan? x)`

Defined at lib/math/init.lisp:51:2

Is `X` equal to NaN?

### Example

``````> (nan? (/ 0 0))
out = true
> (nan? 1)
out = false
``````

## `(odd? x)`

Defined at lib/math/init.lisp:39:2

Is `X` an odd number?

### Example

``````> (odd? 1)
out = true
> (odd? 2)
out = false
``````

## `(pred x)`

Defined at lib/math/init.lisp:67:2

Return the predecessor of the number `X`.

## `(round x)`

Defined at lib/math/init.lisp:96:2

Round `X`, to the nearest integer.

### Example:

``````> (round 1.5)
out = 2
> (round 1.3)
out = 1
> (round -1.3)
out = -1
``````

## `(succ x)`

Defined at lib/math/init.lisp:63:2

Return the successor of the number `X`.