public static double nextDown (double d)

Returns the floating-point value adjacent to ` d`

in
the direction of negative infinity. This method is
semantically equivalent to ```
nextAfter(d,
Double.NEGATIVE_INFINITY)
```

; however, a
` nextDown`

implementation may run faster than its
equivalent ` nextAfter`

call.

Special Cases:

- If the argument is NaN, the result is NaN.
- If the argument is negative infinity, the result is negative infinity.
- If the argument is zero, the result is
`-Double.MIN_VALUE`

`d` | starting floating-point value |

Diagram: Math