Floating Point Arithmetic

[DavePearce]

See this on how to concisely convert floating point arithmetic into BigRational:

https://stackoverflow.com/questions/63975340/convert-double-into-bigrational-two-biginteger-for-numerator-denominator?noredirect=1#comment113136150_63975340

See also this:

A Novel Approach to Generate Correctly Rounded Math Libraries for New Floating Point Representations, JAY P. LIM, MRIDUL AANJANEYA, JOHN GUSTAFSON, SANTOSH NAGARAKATTE.