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1. 3. 2008.
Book Review
Sharkovsky’s Theorem and the ‘Period three implies chaos’ result of Li and Yorke, are profound and deep results showing the rich periodic character of first-order, non-linear difference equations. The (3x þ 1)-conjecture of L. Collatz is one of the most challenging problems of contemporary mathematics. In the authors’ words, ‘During the last ten years, we have been fascinated discovering non-linear difference equations of order greater than one which for certain values of their parameters have one of the following characteristics: