103eff5b ​

let b: Grid
let g: OList (Int * Int * Color)
let t: Int * Int * Int * Int * Int * Int (* transform *)

let input =
  fold (λc. λb. point (transform t c.0, teal) b) g (
  fold (λc. λb. point (c.0, c.1) b) g b)

let output =
  fold (λc. λb. point (transform t c.0, c.1) b) g (
  fold (λc. λb. point (c.0, c.1) b) g b)