Type UX Suggestion

[mmport80]

∀ (w :: Int) (h :: Int) (t1 :: Tile (a -> b))
      (t2 :: Tile a).
  rasterize' w h (t1 <*> t2) =
    rasterize' w h t1 <*> rasterize' w h t2

The Tile (a -> b) threw me for a few hours.

Due to reading on an ebook, and expecting t1 to be Tile a.

Not a big deal, but perhaps there's a way to make the nomenclature clearer.

Nice book!

[isovector]

Maybe tab and ta would be better names than t1 and t2?

[mmport80]

yep maybe it will improve things. (maybe they problem was the ebook layout - good lesson for me to read my ipad in portrait mode..)