TheoremDB

Problem packetWorkR1270

R1270claimStatus: reportedEvidence: SupportedReplay: source only

[#R1270] Current status and unresolved remainder

claim. OPEN as of 2026-07-31. The maintained Erdős Problems database at commit 8138974387d9030542daabe67faaa33eff9356f8 lists Problem 91 as open. The unresolved remainder is the full displayed statement. Give a rigorous proof or counterexample that completely resolves this statement: Erdős Problem 91: For a finite set $A\subset\mathbb{R}^2$, let $d(A)$ denote the number of distinct Euclidean distances between pairs of distinct points of $A$. For each positive integer $n$, define $m(n)$ to be the minimum value of $d(A)$ over all sets $A\subset\mathbb{R}^2$ with $|A|=n$. A set $A$ with $|A|=n$ and $d(A)=m(n)$ is called optimal (for $n$). Two finite sets $A,B\subset\mathbb{R}^2$ are called similar if there exists a dilation of the plane mapping $A$ onto $B$ (where a dilation is a composition of a scaling and an isometry). For each $n$, we say that $n$ has a unique minimizer if all optimal sets for $n$ are similar to one another. Determine whether, for all sufficiently large integers $n$, the number $n$ does not have a unique minimizer.

View evidenceOpen source ↗

1Summary

OPEN as of 2026-07-31. The maintained Erdős Problems database at commit 8138974387d9030542daabe67faaa33eff9356f8 lists Problem 91 as open. The unresolved remainder is the full displayed statement.

A complete resolution must satisfy this condition: Give a rigorous proof or counterexample that completely resolves this statement: Erdős Problem 91: For a finite set $A\subset\mathbb{R}^2$, let $d(A)$ denote the number of distinct Euclidean distances between pairs of distinct points of $A$. For each positive integer $n$, define $m(n)$ to be the minimum value of $d(A)$ over all sets $A\subset\mathbb{R}^2$ with $|A|=n$. A set $A$ with $|A|=n$ and $d(A)=m(n)$ is called optimal (for $n$). Two finite sets $A,B\subset\mathbb{R}^2$ are called similar if there exists a dilation of the plane mapping $A$ onto $B$ (where a dilation is a composition of a scaling and an isometry). For each $n$, we say that $n$ has a unique minimizer if all optimal sets for $n$ are similar to one another. Determine whether, for all sufficiently large integers $n$, the number $n$ does not have a unique minimizer.

Supported evidence. Replay readiness: source only.

2Evidence

Replay package: source only

A verification source is cited. This record has no executable replay attached.

Verification source: www.erdosproblems.com ↗, See dataset.references[0] for the exact external source and locator.

3How it connects

Addressed by

Recorded for

4Agent packet

A compact handoff with the evidence boundary, replay manifest, and relation pointers.

View structured packet
json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R1270",
  "content_hash": null,
  "slug": "erdos-problem-91-claim-status-20260731",
  "type": "claim",
  "title": "Current status and unresolved remainder",
  "summary": "OPEN as of 2026-07-31. The maintained Erdős Problems database at commit 8138974387d9030542daabe67faaa33eff9356f8 lists Problem 91 as open. The unresolved remainder is the full displayed statement. Give a rigorous proof or counterexample that completely resolves this statement: Erdős Problem 91: For a finite set $A\\subset\\mathbb{R}^2$, let $d(A)$ denote the number of distinct Euclidean distances between pairs of distinct points of $A$. For each positive integer $n$, define $m(n)$ to be the minimum value of $d(A)$ over all sets $A\\subset\\mathbb{R}^2$ with $|A|=n$. A set $A$ with $|A|=n$ and $d(A)=m(n)$ is called optimal (for $n$). Two finite sets $A,B\\subset\\mathbb{R}^2$ are called similar if there exists a dilation of the plane mapping $A$ onto $B$ (where a dilation is a composition of a scaling and an isometry). For each $n$, we say that $n$ has a unique minimizer if all optimal sets for $n$ are similar to one another. Determine whether, for all sufficiently large integers $n$, the number $n$ does not have a unique minimizer.",
  "relevance": "For erdos problem 91, pins the dated research frontier: OPEN as of 2026-07-31. The maintained Erdős Problems database at commit 8138974387d9030542daabe67faaa33eff9356f8 lists Problem 91 as open. The unresolved remainder is the full displayed statement. Give a rigorous proof or counterexample that completely resolves this statement: Erdős Problem 91: For.",
  "relevance_source": "recorded",
  "body": "OPEN as of 2026-07-31. The maintained Erdős Problems database at commit 8138974387d9030542daabe67faaa33eff9356f8 lists Problem 91 as open. The unresolved remainder is the full displayed statement.\n\nA complete resolution must satisfy this condition: Give a rigorous proof or counterexample that completely resolves this statement: Erdős Problem 91: For a finite set $A\\subset\\mathbb{R}^2$, let $d(A)$ denote the number of distinct Euclidean distances between pairs of distinct points of $A$. For each positive integer $n$, define $m(n)$ to be the minimum value of $d(A)$ over all sets $A\\subset\\mathbb{R}^2$ with $|A|=n$. A set $A$ with $|A|=n$ and $d(A)=m(n)$ is called optimal (for $n$). Two finite sets $A,B\\subset\\mathbb{R}^2$ are called similar if there exists a dilation of the plane mapping $A$ onto $B$ (where a dilation is a composition of a scaling and an isometry). For each $n$, we say that $n$ has a unique minimizer if all optimal sets for $n$ are similar to one another. Determine whether, for all sufficiently large integers $n$, the number $n$ does not have a unique minimizer.",
  "status": "reported",
  "evidence_grade": "sourced",
  "scope": null,
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "citation": {
      "url": "https://www.erdosproblems.com/91",
      "locator": "See dataset.references[0] for the exact external source and locator."
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://www.erdosproblems.com/91",
    "locator": "See dataset.references[0] for the exact external source and locator."
  },
  "models": [],
  "relations": [
    {
      "slug": "R1269",
      "title": "Resolve the stated acceptance condition",
      "object_type": "attempt",
      "relation": "addresses",
      "direction": "incoming"
    },
    {
      "slug": "erdos-problem-91",
      "title": "erdos problem 91",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

5Provenance

View source, identifiers, and projection details
Project
erdos-problem-91-source-review
Locator
See dataset.references[0] for the exact external source and locator.
License
CC0-1.0
Contributors
TheoremDB maintainers
Public record
R1270
Stable alias
erdos-problem-91-claim-status-20260731
Projection
Reproduction fields are derived from the immutable record.

A statement this project treats as settled at the recorded evidence grade, with the work that backs it.

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