If only multiplication and division are allowed, I'm willing to posit that this challenge is unsolvable. You are asking for an expression of the following form to produce addition and subtraction:I won't hold my breath on that one.Code:operand[*,/]operandoperand-> a constant, one of the inputs, oroperand[*,/]operand

I will share my original thoughts. Since a double contains 11 bits of exponent, that part of a double can be used as an accumulator through multiplication. Note that not all states of the 11 bits are valid; I originally planned to only use 10 bits to avoid the NaN and infinity states. After building a 10-bit accumulator, it's a simple step to cascade five of them, add a three bit accumulator for the last three bits that the fraction part of a double can contain, and perform the addition in that context. This required the comparision operators to check to see if the initial state of the exponent was 0 since multiplying 0 by 2 wouldn't produce any usable input. The assignment operator was necessary to assign the first 1 into an empty accumulator.

Of course, with the comparision and assignment operators, you really don't need anything that convolted. A union with a bit field (with each bit as its own field) and a 64-bit integer would provide the space needed to perform the addition.