## bool-vector-union

**bool-vector-union**is a built-in function in `

`C source code`

'.(bool-vector-union

__A__

__B__&optional

__C__)

Return

__A__|

__B__, bitwise or.

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.