Union closed sets conjecture (6a)

Union closed sets conjecture

Upper bound, last-listed row

| $1/2 = 0.5$ | [F1995] | Conjectured (in 1976) to be optimal |tracked since 2026-07-24 — no movement seen yet

Lower bound, last-listed row

| $0.38271$ | [L2023] |tracked since 2026-07-24 — no movement seen yet

Cite this row

Bounds Ledger — Union closed sets conjecture (6a)
upper bound: $1/2 = 0.5$ (tracked since 2026-07-24 — no movement seen yet)
lower bound: $0.38271$ (tracked since 2026-07-24 — no movement seen yet)
Mirrored from teorth/optimizationproblems@2c1968c. These are the last-listed rows of that constant's bounds table — a listing position, not a statement that this bound is the strongest or most recent. A snapshot at that sha, not a live read.
https://u00dxk2.github.io/bounds-ledger/c/6a.html