The FIRST thing that came to mind when I read that headline was Hofstadter's Contracrostapunctus in THAT book!
Check it out! Read it! And if you DON'T find the WHOLE hidden message, read it again, because it's spelled out RIGHT in the dialog!
Happy hunting!
An article referring to:
{e ∈ GEB|HN: e := article referring to GEB}
... might be considered rather self referential (especially if I have got my rather dodgy notation right). Note how I leave out several important definitions and leave them to your imagination. I will resort to hand-waving as required.
Hmmm: FIRST, THAT, DON'T, WHOLE, RIGHT. I speak en_GB you monster!