| Slash | / | 
Monadic Slash is not defined
      3 1 ¯2 2 / 6 7 8 9
6 6 6 7 0 0 9 9
      1 0 1 0 1 / 'Heart'
Hat
        Slash is a Monadic operator with a Dyadic operand
      +/ 1 2 3 4 5
15
      2 +/ 1 2 3 4 5   ⍝ pair-wise sum
3 5 7 9
      cube    ⍝ 3D array
 1  2  3  4
 5  6  7  8
 9 10 11 12
           
13 14 15 16
17 18 19 20
21 22 23 24
      +/ cube
10 26 42
58 74 90
      +/[1] cube    ⍝ sum of planes
14 16 18 20
22 24 26 28
30 32 34 36
      +/[2] cube    ⍝ column sums
15 18 21 24
51 54 57 60