0bb8deee ​

let g1: Grid mono
let g2: Grid mono
let g3: Grid mono
let g4: Grid mono
let p1: Loc
let p2: Loc
let p3: Loc
let p4: Loc
let vl: Int * Cell
let hl: Int * Cell

let input = g
  |> hline hl.0 0 -1 vl.1
  |> vline 0 -1 vl.0 vl.1
  |> grid p1 g1
  |> grid p2 g2
  |> grid p3 g3
  |> grid p4 g4

let output =
  hcat [vcat [g1, g2], vcat [g3, g4]]