`decode-float', which breaks an IEEE-float into its constituentsign, exponent and mantissa, is very useful and worth specifying.See the portable call-with-mantissa&exponent implementation from SRFI 56.
What's the rationale for the constants instead of the expressions?If we keep them it's worth noting that e is (flexp 1.0).
Also I thinktau is more useful than pi (http://tauday.com/) and worth defining.
Also consider defining the machine epsilon (DBL_EPSILON).
Could you provide an example for:Flonum operations must be at least as accurate as their genericcounterparts applied to flonum arguments. In some cases,operations should be more accurate than their naive genericexpansions because they have a smaller total roundoff error.