## UNION-EQ

union of two lists of symbols
Major Section: PROGRAMMING

`(Union-eq x y)`

equals a list whose members
(see member-eq) contains the members of `x`

and the members
of `y`

. More precisely, the resulting list is the same as one
would get by first deleting the members of `y`

from `x`

, and then
concatenating the result to the front of `y`

.

The guard for `union-eq`

requires both arguments to be true lists,
but in fact further requires the first list to contain only symbols,
as the function `member-eq`

is used to test membership (with
`eq`

). See union-equal.