arXiv · math/0511009
We deduce a recent theorem by R. Schwartz on the structure of the so-called Poncelet grid from complete integrability of the billiard in an ellipse
M. Levi, S. Tabachnikov. 2005-11-01. The Poncelet grid and the billiard in an ellipse. https://arxiv.org/abs/math/0511009
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