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Source. The paragraph on p. 43 following the proof of the Anning--Erdős theorem, of P. Erdős, Combinatorial problems in geometry, Math. Chronicle 12 (1983), 35--54, the transcript of an invited address at the 17th New Zealand Mathematics Colloquium (Dunedin, 17--19 May 1982), as named on the source card. The lecture numbers none of its statements; the pages are the journal's own.

Statement

Problem (p. 43). Erdős notes that it is easy to place $n$ points on a circle with all distances integers, and asks whether one can find $n$ points in general position, which he glosses as "no three on a line, no four on a circle", with all distances integers.

Reported state (p. 43). Harborth settled the case $n=5$; the general case, even $n=6$, was not known. Erdős adds that it is probably difficult because it belongs to Diophantine approximation.

Read depth. Claims checked: the passage was read clause by clause on the page images of the print. A second reader checked the statement, hypotheses, label and page against the print.

Proof pointer

The paper proves nothing about the problem.

Dependencies

theorem_p42 is the context: an infinite such set must be collinear.

Bears on

• Problem 213: the lecture poses the problem's question for every $n$ and reports the case $n=5$ as settled by Harborth and $n=6$ as open at the time. It proves nothing toward it.