Cover    Chapter I    Chapter II    Chapter III     Maple Package

Introduction to Shalosh B. Ekhad's

"90 Ring Ring Problems"


Written: July 5, 2021

The Rules

Fill the empty cells of the grid by drawing rectangles consisting of horizontal and vertical lines passing through the cells' centers. The lines of the rectangles may cross but do not overlap. Corners of rectangles may not touch.

To get an idea, simply look at the this problem and its solution.

[Note: these puzzles appears currently (starting June 2021) in the New York Times Sunday magazine, and are attributed there to Prasanna Seshadri.]

The Maple package

In order to use the Maple package RingRing.txt, just download it, and follow the on-line instructions. Have fun! Of course, you need to have the computer algebra system Maple on your computer.

Cover    Chapter I    Chapter II    Chapter III    Chapter IV