Problem · problem
Union-closed sets conjecture
For decades nobody could prove any constant fraction. In 2022 Justin Gilmer, then at Google, proved 1%, using an information-theoretic argument. Within weeks others pushed it to about 38%. The last stretch to 50% appears to need a new idea.
Posed 1979, Péter Frankl.
What would settle it
Lean statement in formal-conjectures
Sources
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