Exact logarithmic numbers #
The exact value set is zero together with the signed integral powers ±β^e of the radix β,
with e an unbounded integer. Multiplication is the only arithmetic operation supplied, and it is
exact because signs combine and exponents add. General addition and conversion into this value set
require rounding: a sum of radix powers need not be a radix power. Division by a nonzero value
could subtract exponents exactly, but division and its zero-divisor policy are not implemented.
The family supplies a
configured ExecFloat.Logarithmic carrier, proof automation, and #float_info support.
References #
- E. E. Swartzlander Jr. and A. G. Alexopoulos, “The Sign/Logarithm Number System,” IEEE Transactions on Computers C-24(12), 1975.