findall(a, f)
Returns an array with all entries a[i] such that f(a[i]) is true.
findall(a, f, i)
As above but search starts at index i.
See also find match matchcount
Example
f(x) = x>5
a = ( 1, 2, 7, 9 )
1 2 7 9
findall( a, f )
7 9