On the maximum tolerable noise for reliable computation by formulas
Bruce Hajek, T. Weller · IEEE Transactions on Information Theory · 1991
It is shown that if formulas constructed from error-prone three-input gates are used to compute Boolean functions, then a per-gate failure probability of 1/6 or more cannot be tolerated. The result is shown to be tight if the per-gate failure probability is constant and precisely known.>