ChrisJ
May 11th, 2019, 01:16 AM
Here is a link to a nice video story about Japanese Hagaromo Fulltouch Chalk, so much preferred by some Mathematicians that they started to hoard it when it went out of production.
"The legend around this chalk is it's impossible to write a false theorem [with it]"
https://www.greatbigstory.com/stories/the-rolls-royce-of-chalk
"The legend around this chalk is it's impossible to write a false theorem [with it]"
https://www.greatbigstory.com/stories/the-rolls-royce-of-chalk