[[a b]:
  [[b a gte?]  [a]
   [otherwise] [b]] ?
] [max] def

[[dup length 1 lt?] [[max] doin] while ...] [maximum] def

[[a b]:
  [[b a lte?]  [a]
   [otherwise] [b]] ?
] [min] def

[[dup length 1 lt?] [[min] doin] while ...] [minimum] def