Erdős problem 94
Suppose points in determine a convex polygon and the set of distances between them is . Suppose appears as the distance between many pairs of points. Then
- Formal statements
- 1 open · 2 solved · 1 test
- Erdős Problems says
- proved (Lean)
- Decision here
- accepted
- Checks
- 2 checks · 4 formal
For every finite planar point set P, the sum over its distinct determined distances of the unordered-pair distance multiplicities equals P.card.choose 2
Still unresolved: That occurrence is one of four Erdős 94 declarations Formal Conjectures publishes, and this identity does not establish the cubic distance-multiplicity conjecture.
Exact result and limitations
At lean-proofs commit 423344341fbfdf4f8f684a302c5d05379125e7dc, Erdos94.variants.sum_multiplicity proves that for every finite planar point set P, the sum over its distinct determined distances of the unordered-pair distance multiplicities equals P.card.choose 2, matching Formal Conjectures commit 94a278e06a8bcbc2e4f2935e491c0c115ec832e0. For occurrence resolution only, the exact occurrence Erdos94.erdos_94.variants.sum_multiplicity is associated with problem:erdos:94 under resolver entity root sha256:32f6e98a826da23c12c7cfcb8853e4712de130136c59f0454bd115c3fdb1e6b1. That occurrence is one of four Erdős 94 declarations Formal Conjectures publishes, and this identity does not establish the cubic distance-multiplicity conjecture.
- An exact evidence file is bound to this Result; its recorded path remains in the technical record.
- Occurrence association with problem:erdos:94 is navigation-only and establishes no statement identity or semantic equivalence.
- Caveat: This proves only the elementary sum_multiplicity identity, not the cubic Erdős 94 theorem or either other variant.
- Caveat: The Formal Conjectures build needs the mechanical Sym2.mk.uncurry to Sym2.mk API spelling change between its pinned Mathlib and lean-proofs.
- Caveat: No external source-owner review, human review, upstream acceptance, or external adoption occurred.
- Caveat: Producer checks are not Verification, Decision, or Standing.
- Type
- theoretical
- Evidence
- 3 artifacts
- Decision
- accepted
- Reviewed
- Aug 18, 2026, 6:46 PM