I've blogged about this gem from Lothar Collatz (1910-1990) before, but it deserves to be repeated. Especially since it now provides an elegant example of singleton expansion.... read more >>

(A slight revision of the post I made a few hours ago.)... read more >>

Today is Friday, March 13, 2020. In many parts of the world, Friday the 13th is considered unlucky. I've written blog posts about Friday the 13th before, 2012, 2018, but I will have something new to say today.... read more >>