Every vertex has an even degree, yet the picture cannot be drawn with a single stroke.
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Joe Celko looks at four different abacuses used throughout history
Chalkdust issue 17 – Coming 22 May
Pre-order a copy and/or book your ticket for our launch event
Book of the Year 2020
We announce the winner of this coveted prize
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Tony Pisculli dissects the lyrics from a popular song
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What can a 100-year-old result in topology say about weather and computers?
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