RemoveIf
Removes, from a container, every element that satisfy a given predicate.
Syntax

RemoveIf(X, p[, n])

X
is any container that is not a set 
p
is a predicate 
n
is a positive integer


RemoveIf(S, p)

X
is a set 
p
is a predicate

Description
If X
is any container (including a set), then RemoveIf(X, p)
returns X
with every element x
for which p(x)
is true
removed. If X
is not a set, then RemoveIf(X, p, n)
removes elements that satisfy p
at level n
, with level n = 1
being X
itself.
Examples
v ≔ RandomIntVector(20, −3, 4)
(2, −2, 1, −2, 3, 1, −2, 0, −3, 3, 1, 3, 3, 1, −2, 2, 0, 0, 3, 3)
RemoveIf(v, odd)
(2, −2, −2, −2, 0, −2, 2, 0, 0)
compute(RandomIntVector(20, −3, 4), n, 1, 5)
(−1, −3, −2, 1, 1, 2, −1, −3, 2, 3, 2, −3, 2, −2, −3, 3, 1, −3, −1, −1) (2, −1, 3, 3, 0, −2, 0, 1, 0, −2, 2, −3, −1, 3, 1, 0, −3, 1, 3, 1) (1, 0, 3, −2, −1, 2, 2, 3, 1, 1, 1, −2, −2, −1, −1, −3, 3, −1, 0, 3) (−1, −1, 0, 3, 2, 1, 3, 0, 2, −1, −2, 1, 2, 3, −2, 2, 0, 2, 0, −1) (2, −1, 2, 3, 2, 2, −2, 0, 0, 1, −1, −3, 2, −1, 1, 1, 0, 0, 3, −1)
RemoveIf(ans, odd, 2)
(−2, 2, 2, 2, 2, −2) (2, 0, −2, 0, 0, −2, 2, 0) (0, −2, 2, 2, −2, −2, 0) (0, 2, 0, 2, −2, 2, −2, 2, 0, 2, 0) (2, 2, 2, 2, −2, 0, 0, 2, 0, 0)