Erdős problem 751 · problems.science

Let $G$ be a graph with chromatic number $\chi(G)=4$ . If $m_1<m_2<\cdots$ are the lengths of the cycles in $G$ then can $\min(m_{i+1}-m_i)$ be arbitrarily large? Can this happen if the girth of $G$ is large?

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FormalConjectures/ErdosProblems/751.lean

Formal Conjectures

FormalConjectures/ErdosProblems/751.leanErdos751.erdos_751.parts.i1 lineExact file

1False ↔ ∀ (k : ℕ), ∃ V G, G.chromaticNumber = 4 ∧ ∀ m ∈ G.cycleLengths, ∀ m' ∈ G.cycleLengths, m < m' → m + k ≤ m'

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Jayyhk Erdős Leanjayyhk:erdos:751
PLBY Lean proofsErdosProblems.Erdos751

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Erdős AI contributions wiki · 27 Jan, 2026
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GPT-5.2-Codex, GPT-5.2 Thinking
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