# double not boolean expression

# empty configs are not accepted by Kea
default-lease-time 1800;

# use double not in a reductible match if
class "reductible" {
    match if not (not ((option host-name = "www.example.com") or
                       (option host-name = "www.example.org")));
}

# use not with !=
class "other" {
    match if not (option host-name != "www.example.com");
}