g can be any monadic function which returns a result. Y can be any array appropriate to function g with gY being suitable as the right argument to function f.

If X is omitted, f must be a monadic function. If X is specified, f must be a dyadic function and X can be any array that is suitable as the left argument to function f.

The derived function is equivalent to fgY or XfgY and need not return a result.

The Beside operator allows functions to be glued together to build up more complex functions. For further information, see Function Composition.

      RANK ← ⍴∘⍴
      RANK ¨ 'JOANNE' (2 3⍴⍳6)
 1  2

      +/∘⍳¨2 4 6
3 10 21
 
 
      ⎕VR'SUM'
     ∇ R←SUM X
[1]    R←+/X
     ∇
 
      SUM∘⍳¨2 4 6
3 10 21

      +∘÷/40⍴1       ⍝ Golden Ratio! (Bob Smith)
1.618033989
 
      0,∘⍳¨⍳5
0 1  0 1 2  0 1 2 3  0 1 2 3 4  0 1 2 3 4 5