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Conjecture

Conway's Thrackle Conjecture

Combinatorics

A thrackle is an embedding of a graph in the plane in which every pair of edges meets exactly once, either at a shared endpoint or at a single transverse crossing point in their interiors. Conway's thrackle conjecture, proposed by John H. Conway, states more generally that every thrackle has at most as many edges as vertices. It remains open; it is known only that the number of edges in a thrackle is at most a constant multiple of the number of vertices. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/

Facts
Statement
In any thrackle, the number of edges is at most equal to the number of vertices. 1
Prize Status
A prize of 1000 dollars was offered by John H. Conway for proving or disproving the conjecture; unclaimed, since the conjecture remains open. 1
Progress Toward Resolution
Open. The current record bound is 1.393n edges for a thrackle with n vertices. 1
Classification
Resolution Status
Open 1
Prize Status
Prize Status (category)
Prize Offered, Unclaimed 1
Connections

Posed By

Sources
1. Conway's Thrackle Conjecture (Wikipedia)
Wikimedia Foundation
  • Lead section
    John H. Conway conjectured more generally that every thrackle has at most as many edges as vertices.
  • Thrackle conjecture section
    John H. Conway conjectured that, in any thrackle, the number of edges is at most equal to the number of vertices.
  • Progress section, Fulek and Pach
    the current record is 1.393n
  • Thrackle conjecture section, prize sentence
    Conway offered a $1000 prize for proving or disproving this conjecture
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