On: Seven deadly sins of talking about “types” (2014)

Wow, that link is really something. I never would have thought that someone would release code into the wild without ever running it.

Donald Knuth, IIRC, once said, "Be cautious running the following code; I have only proven it correct, not tested it."

"Beware of bugs in the above code. I have only proved it correct, not tried it."

http://www-cs-faculty.stanford.edu/~uno/faq.html