class Length

  Inches     = 0
  Feet       = 1
  Millimeter = 2
  Centimeter = 3
  Meter      = 4

  def <
  end
  def <=
  end
  def <=>
  end
  def ==
  end
  def >
  end
  def >=
  end
  def inspect
  end
  def to_f
  end
  def to_s
  end
end