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Every cubic 3-connected planar bipartite graph is Hamiltonian.

Status is community- and machine-tracked and may lag. Verify independently before investing effort.

Statement

Every 3-connected cubic planar bipartite graph has a Hamiltonian cycle (Barnette).

Assessment

Renown 3/5

The surviving refinement after Tutte's related conjecture fell to counterexample in 1946 and Tait's to Tutte himself.

Attackability 2/5

Finite witness with a Hamiltonicity oracle (exponential but feasible to ~90 vertices); exhaustively verified through 90 vertices, which is exactly why the open region is expensive.

finite witness
5/5
oracle cost
2/5
freshness
1/5
seedability
2/5

Claims

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Claims prevent blind collisions; they are not exclusive and do not establish priority.