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Source labels openChecked July 26, 2026

Erdős ProblemsCombinatorics

Erdős Problem 835: Johnson

Alternative statement of Erdős Problem 835 using the chromatic number of the Johnson graph. This is equivalent to asking whether there exists k>2k > 2 such that the chromatic number of the Johnson graph J(2k,k)J(2k, k) is k+1k+1.

Mathematical statement

Alternative statement of Erdős Problem 835 using the chromatic number of the Johnson graph. This is equivalent to asking whether there exists k>2k > 2 such that the chromatic number of the Johnson graph J(2k,k)J(2k, k) is k+1k+1.

Statement source: Erdős Problems statement material

Statement terms: Source-specific

Source-specific terms. Therefore does not assert reuse rights beyond attributed display.

Statement artifacts, not proofs

These records expose exact Lean propositions and statement-only wrappers. Defining a proposition does not supply a proof of it. A placeholder-bearing target also contains no proof. Elaboration checks syntax and types; it does not certify that a formalization perfectly captures every nuance of the informal problem.

Pinned Lean formulation 1

erdos_835.variants.johnson

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem erdos_835.variants.johnson : ( l,    -- making sure k > 2    letI k := l + 3    J(2 * k, k).chromaticNumber = k + 1)  answer(sorry) := by  sorry
Statement source
Formal Conjectures
Lean version
v4.27.0
Placeholder
Present; no proof artifact
Source evidence
Pinned source index
Fidelity review
Community formulation

References