On Sat, Jun 17, 2017 at 06:17:24PM +0800, Elias Mårtenson wrote: > I'm sure there was a function that could do this, but for the life of me > can't figure out which one it was.
It was dyadic reduce operator:
3,/⍳6
1 2 3 2 3 4 3 4 5 4 5 6
-k
