Monotile:Congruent plane figures of a single type that covers an infinite geometric plane without gaps or overlaps.

This figure was called 'eistein' until it was discovered.

It is important to notice that flipping is used.In the diagram,the dark blue blocks are the result of flipping blocks of others. Mathematicians have proven that there is no aperiodic monotile if only translations are allowed and no flipping is allowed.The only question that remains is whether such a monotile exists if no flipping is allowed, but translations and rotations are allowed.

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