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General community for all things mathematics on @lemmy.world

Submit link and text posts about anything at all related to mathematics.

Questions about mathematical topics are allowed, but NO HOMEWORK HELP. Communities for general math and homework help should be firmly delineated just as they were on reddit.

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How a Doodler's Problem Sparked a Controversy in Math | Scientific American (www.scientificamerican.com)

submitted 1 year ago by troyunrau@lemmy.ca to c/math@lemmy.world

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Four colour problem

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[–] person594@feddit.de 3 points 1 year ago (1 children)

On a torus, you can have up to seven mutually adjacent regions. See https://upload.wikimedia.org/wikipedia/commons/3/37/Projection_color_torus.png

[–] troyunrau@lemmy.ca 2 points 1 year ago

Oh, very nice!