Erdős problem 1068

Does every graph with chromatic number $\aleph_1$ contain a countable subgraph which is infinitely connected?

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1068.lean

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Does every graph with chromatic number $\aleph_1$ contain a countable subgraph which is infinitely connected?

FormalConjectures/ErdosProblems/1068.leanErdos1068.erdos_10683 linesExact file

1True ↔2  ∀ (V : Type) (G : SimpleGraph V),3    G.chromaticCardinal = Cardinal.aleph 1 → ∃ s, s.Countable ∧ (SimpleGraph.induce s G).InfinitelyConnected

OpenStatement only, no proof