SCHWEITZER 1999 Problem 1
Call a subset of the plane a circular set iff there exists a point such that for every ray starting from it, the ray intersects the subset once. show that the plane is a countable union of circular sets.
Dataset text AI-MO AoPS. Quoted with source.
Solutions
No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.
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