[jjoonathan]

I think you'd use all the mass in the observable universe long before the GNU Multi-Precision library started sweating :)

[eru]

If you were naive. You can probably cheat (ie be more clever in your construction).

[jjoonathan]

I suspect that once you had found a way to get the asymptotic cost growth under control you would find you had build a digital mechanical calculator.

[eru]

My money would be on that as well, though not at crazy odds.