The Over () operator

The Over operator the only composition that can apply the same function twice.

To mimic Over in Dyalog 17.1, a programmer would have to write a user-defined operator, or make an array and use Each!

handrank{{((8|@12-/).=¨1,⊃){(/),(2=≢),,⊂[;]⍺},⍺}/↓⍉[;]}
cmp  {⍺⍵-(⊃⍋)⍵⍺}
cmphand  cmp  handrank
      (5 2'6♡6♣6♢K♡K♠') cmphand(disp¯1) (5 2'A♠2♠3♣4♠5♢')
¯1