If you wanted to put source code on a t-shirt, what would you write?

I'll try to clarify here. I don't mean a whole file. More just a single expression that other devs would understand. eg. (+ 1 2) or the ternary operator or something.

there's the classic: https://www.wired.com/2000/08/court-to-address-decss-t-shirt...

The original Lisp definitions by McCarthy