⍵⍵
⍵⍵ makes a defined operator dyadic and denotes its right operand.
op←{⍺⍺+⍵⍵×⍵} ⋄ (2 op 3)4 ⍝ 14
Operands can be arrays or functions; arguments remain ⍺ and ⍵.
⍺
⍵