%-

(:def fst
  (:lambda xy (text, text)
    (:match xy
      [(x, _) x])))

(:def snd
  (:lambda xy (text, text)
    (:match xy
      [(_, y) y])))

(:def fst3
  (:lambda xyz (text, text, text)
    (:match xyz
      [(x, _, _) x])))