There are two ways to write error free programs; only the third one works–Alan Perlis

Alan Perlis, the first Turing Award winner, summarized the whole issue of program correctness in his single quote. Maybe there is nothing more to say about it.

But this coming Thursday, if you want to hear more about it, you can tune in for a debate with Rich de Millo and myself. It will be 7:00–8:30pm Eastern time.

Harry Lewis of Harvard University will moderate. It will be broadcast LIVE HERE. It’s free.

The Paper

Perlis and Rich DeMillo and I wrote the paper “Social Processes and Proofs of Theorems
and Programs” in the middle of the second half of the last century—pushing towards fifty years ago. We were responding to the then-common view that programs should be proved correct—proved in the same manner that one proves theorems like:

Theorem 1 (Euclid) There are an infinite number of prime numbers.

We begged to object: We felt that correctness of programs was fundamentally a different issue. This is what the debate is all about.

The debate will give us all a chance to reflect now almost 50 years later when programs enrich and regulate so much more of our lives. Perhaps the real winner in society goes according to the proverb: “the one who ends up with the most toys.” In that case, Harry the moderator will win hands down:

The Writing

Mary-Claire van Leunen is an expert on writing, especially for technical articles. See her famous book.

The article was heavily written by Rich with input from Alan and myself. The ideas are due to all of us. The actual details, the words, the punctuation owe more to Rich with strong input from Mary-Claire.

Our paper is one of forty-six papers included in the book Ideas That Created the Future: Classic Papers of Computer Science, which was edited by Harry for MIT Press (2020). They are presented in chronological order beginning with Aristotle (~350 BCE). The median year is 1962-63.

Open Problems

See How to Have Your Abstract Rejected for a tongue-in-cheek view of writing technical material. It was written by Mary-Claire and myself.

See you Thursday.