Comment by tromp
If the IOCCC description [1] doesn't make it clear enough, perhaps this explanation [2] does it better? I also link to a Pi Day 2023 talk trying to explain it on my lambda playground page [3].
[1] https://www.ioccc.org/2012/tromp/
[2] https://gist.github.com/tromp/86b3184f852f65bfb814e3ab0987d8...