///|
pub let rat_zero : @rational.BigRational = @rational.new(0N, 1).unwrap()

///|
pub let rat_one : @rational.BigRational = @rational.new(1N, 1).unwrap()

///|
pub let rat_two : @rational.BigRational = @rational.new(2N, 1).unwrap()

///|
pub let rat_neg_one : @rational.BigRational = @rational.new(-1N, 1).unwrap()