Programming with Gaussian logarithms to compute the approximate addition and subtraction of very small (or very large) positive numbers

Computations involving very small (or very large numbers) can produce underflow (or overflow) errors, even when these numbers are represented as logarithms. When logarithmic representation is used, algorithms to effect addition and subtraction remain limited in range by underflow or overflow. The algorithms presented here extend the range of these operations to allow computations on smaller (or larger) numbers.