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Erdős problem 224

If A⊆RdA\subseteq \mathbb{R}^d is any set of 2d+12^d+1 points then some three points in AA determine an obtuse angle.

No current result

No reviewed Result is current in Vela Mathematics Program. Retained source material is shown below.

Retained declaration

FormalConjectures/ErdosProblems/224.lean

Formal Conjectures

FormalConjectures/ErdosProblems/224.leanErdos224.erdos_2242 linesExact file
∀ {d : ℕ} (A : Finset (EuclideanSpace ℝ (Fin d))),  A.card = 2 ^ d + 1 → ∃ x y z, x ∈ A ∧ y ∈ A ∧ z ∈ A ∧ x ≠ y ∧ x ≠ z ∧ y ≠ z ∧ Erdos224.ObtuseAt x y z
SolvedProof has a holelean4external proof

The proof uses `sorry`: part of the argument is written but not proved. Lean accepts the file; it does not accept the theorem.

Proof manifests naming this Problem

  • Jayyhk Erdős Leanjayyhk:erdos:224
  • PLBY Lean proofsErdosProblems.Erdos224

Reported activity

Work these sources record against this Problem. Source-reported attribution, not reviewed here.

  • AI building on literature

    Erdős AI contributions wiki · 14 Jan, 2026

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    Codex, GPT-5.2 Thinking
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