85b81ff1 ​

let c: Color
let t: OList OList Int

let input = fill 13 (fill 14 black)
  |> fold (λ(r, i). λg. g
    |> rect ((1, i * 3 - 2, -1, i * 3 - 1), c)
    |> fold (λj. point (j * 2, i * 3 - 1) black) r
  ) (index t)

let output = fill 13 (fill 14 black)
  |> fold (λ(r, i). λg. g
    |> rect ((1, i * 3 - 2, -1, i * 3 - 1), c)
    |> fold (λj. point (j * 2, i * 3 - 1) black) r
  ) (index (sort (λr. -len r) t))