A Proof of the Ahlswede-Cai-Zhang Conjecture
Proceedings of the IEEE International Symposium on Information Theory, Honolulu, Hawaii, July 2014

Ahlswede, Cai, and Zhang proved that, in the noise- free limit, the zero-undetected-error capacity is lower-bounded by the Sperner capacity of the channel graph, and they conjectured equality. Here we derive an upper bound that proves the conjecture.