Erdős problem 595 · problems.science

Erdős Problem 595 (250): Is there an infinite graph G which contains no $K_4$ and is not the union of countably many triangle-free graphs?

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7 retained statements2415f78e850a

FormalConjectures/ErdosProblems/

595.lean

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Erdős Problem 595 (250): Is there an infinite graph G which contains no $K_4$ and is not the union of countably many triangle-free graphs?

A problem of Erdős and Hajnal [Er87].

FormalConjectures/ErdosProblems/595.leanErdos595.erdos_5951 lineExact file

1True ↔ ∃ V, ∃ (_ : Infinite V), ∃ G, G.CliqueFree 4 ∧ ¬Erdos595.IsCountableUnionOfTriangleFree G

OpenStatement only, no proof