If I have a function FIB:
∇
[0] R←FIB N
[1] R←0 1
[2] →(N≤¯1+⍴R)/5
[3] R←R,+/¯2↑R
[4] →2
[5] R←R[N+1]
∇
and use ⍤ on it to produce a vector of the fibonacci series from 0 to 9:
(FIB⍤0) ¯1+⍳10
INDEX ERROR+
FIB[5] R←R[N+1]
^^
However:
(FIB⍤0) 0 1 2 3 4 5 6 7 8 9
0 1 1 2 3 5 8 13 21 34
(FIB⍤0) (¯1+⍳10)
0 1 1 2 3 5 8 13 21 34
FIB⍤0 (¯1+⍳10)
0 1 1 2 3 5 8 13 21 34
Best regards,
Louis
