Infinity
ref https://stackoverflow.com/questions/5778295/how-to-express-infinity-in-ruby
PositiveInfinity = +1.0/0.0
=> Infinity
NegativeInfinity = -1.0/0.0
=> -Infinity
CompleteInfinity = NegativeInfinity..PositiveInfinity
PositiveInfinity = +1.0/0.0
NegativeInfinity = -1.0/0.0
CompleteInfinity = NegativeInfinity..PositiveInfinity