The following code returns the expected results: * {⍺+⍵}\⍳10* 1 3 6 10 15 21 28 36 45 55
However, if I also print all the calls, I get a lot more evaluations of the function than expected: *{(⍺+⍵)⊣⎕←('[',(⍕⍺),',',(⍕⍵),']')}\⍳10* [1,2] [2,3] [1,5] [3,4] [2,7] [1,9] [4,5] [3,9] [2,12] [1,14] [5,6] [4,11] [3,15] [2,18] [1,20] [6,7] [5,13] [4,18] [3,22] [2,25] [1,27] [7,8] [6,15] [5,21] [4,26] [3,30] [2,33] [1,35] [8,9] [7,17] [6,24] [5,30] [4,35] [3,39] [2,42] [1,44] [9,10] [8,19] [7,27] [6,34] [5,40] [4,45] [3,49] [2,52] [1,54] 1 3 6 10 15 21 28 36 45 55 This can't possibly be correct? Regards, Elias