decl fruit_cost : Fruit -> Int
def fruit_cost : fruit = {
  var fruit_copy = fruit
  return (match <- fruit_copy with // consuming match
      | $Banana -> 11
      | $Apple | $Orange -> 7)
}

decl amount_to_string : Int -> Bool -> String
def amount_to_string : x is_zero_separated = {
  const ans = match x with
    | 0 ? is_zero_separated -> "Zero"
    | 0 | 1 | 2 | 3 | 4 -> "Few"
    | x ? (5--9).contains: x -> "Several"
    | x ? (10--19).contains: x -> "Pack"
    | _ -> "Lots"
  return ans
}