Every value in array segment
b[1..n]that is not inb[i..j]is inb[i..j].
Let predicate p(v) be "v is in b[i..j]."
(A k: 0<k<=N: ~p(b[k]) -> p(b[k]))
=
(A k: 0<k<=N: ~~p(b[k]) | p(b[k]))
=
(A k: 0<k<=N: p(b[k]) | p(b[k]))
=
(A k: 0<k<=N: p(b[k]))
Every value in array segment b[1..n] that is in b[i..j].