Region Select
A Game Using Knot Theory

How To Play: At the beginning there is a knot figure.
The spaces between the lines are called "regions", and the places where the lines meet are called "crossings".
Each crossing has a "lamp" which can be turned on or off by clicking on the region bordering it.
But when you click on a region, all of its crossing lamps change!
If a lamp is already on, it will be turned off, and if a lamp is off, it will be turned on.
The goal of the game is to light up all of the knot's lamps by clicking on different regions.

Please click a figure to start the game.

The region outside the knot can also be clicked. The region outside the knot can not be clicked.

by Akio Kawauchi, Ayaka Shimizu, Kengo Kishimoto, Japanese Patent Application 2011-95520