til

First x natural numbers

til x    til[x]


Where x is a non-negative integer, returns a vector of the first x integers.

q)til 0
long\$()
q)til 1b
,0
q)til 5
0 1 2 3 4
q)til 5f
'type
[0]  til 5f
^


til and key are synonyms, but the above usage is conventionally reserved to til`.