for

For

n f/y
n f\y

for and scan-for are adverbs that apply a monadic function to a given noun y n times.

For(/) produces a single value, the final value.

Scan-for(\) produces a list of all intermediate values.

 5{1_x}/!10
5 6 7 8 9

 5{1_x}\!10
(0 1 2 3 4 5 6 7 8 9
 1 2 3 4 5 6 7 8 9
 2 3 4 5 6 7 8 9
 3 4 5 6 7 8 9
 4 5 6 7 8 9
 5 6 7 8 9)