Color coding trick yields 2^O(sqrt(n)) depth-3 AC circuits for all symmetric Boolean functions

rrwilliams · x · 2026-09-30

A surprising result in circuit complexity: the Alon-Yuster-Zwick color coding technique can be used to build 2^{O(sqrt(n))}-size depth-3 AC circuits for every symmetric Boolean function.

Ryan Williams calls it the latest exhibit for the idea that "circuit lower bounds are hard to prove because they are false" — upper bounds keep shrinking in ways that defy prior intuition about circuit power.

Related event: Color Coding Yields Smaller Depth-3 Circuits for Symmetric Boolean Functions(2 posts)→

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