# `×` — Sign / Multiply

Function. Keys: `Alt-m`. Ranks: `0` monadic, `0 0` dyadic

`×Y` gives direction: zero, or `Y÷|Y`. The direction of a real number is
an exact integer. Pervasive.

``` bpl
ׯ3 0 4           ⍝ [¯1 0 1]ₓ
×0j2              ⍝ 0j1
```

`X×Y` multiplies. Pervasive.

``` bpl
2ₓ×[1 2 3]ₓ       ⍝ [2 4 6]ₓ
```

## Inverse

`×⁻¹Y` gives back `Y` when `Y` is a possible sign: `¯1`, `0`, `1` or a
unit complex number. With either argument fixed, `×⁻¹` divides by the
fixed argument, which must hold no zero.

``` bpl
×⁻¹¯1    ⍝ ¯1
4×⁻¹12   ⍝ 3
```