Commute {R}←{X}f⍨Y

f may be any dyadic function. X and Y may be any arrays whose items are appropriate to function f.

The derived function is equivalent to YfX. The derived function need not return a result.

If left argument X is omitted, the right argument Y is duplicated in its place, that is:

      f⍨Y ←→ Y f⍨Y

Examples

      N
3 2 5 4 6 1 3

      N/⍨2|N
3 5 1 3

      ⍴⍨3
3 3 3


      mean←+/∘(÷∘⍴⍨) ⍝ mean of a vector
      mean ⍳10
5.5

The following statements are equivalent:

      F/⍨←I
      F←F/⍨I
      F←I/F

Commute often eliminates the need for parentheses