## bool-vector-set-difference

**bool-vector-set-difference**is a built-in function in `

`C source code`

'.(bool-vector-set-difference

__A__

__B__&optional

__C__)

Return

__A__&~

__B__, set difference.

If optional third argument

__C__is given, store result into

__C__.

__A__,

__B__, and

__C__must be bool vectors of the same length.

Return the destination vector if it changed or nil otherwise.