A whistle-stop tour from a deceptively simple Raymond Smullyan logic puzzle — rebuilt live in Ruby with pattern matching — to the very limits of what can be proved or computed: Gödel’s incompleteness theorems, Turing’s halting problem, and the Church–Turing thesis. Rosa’s takeaway: just as mathematics’ existential crisis a century ago gave birth to computer science, understanding the fundamentals yourself is the real advantage in the age of LLMs.

Principal programmer at 37signals who loves learning languages, both for computers and humans, mathematics and theoretical computer science.