Found in 1 comment on Hacker News
kcl · 2007-09-22 · Original thread
For the truly paranoid only:

Witness the evolution of 'V-E+F=2' since Euler's time:

http://www.amazon.com/Proofs-Refutations-Logic-Mathematical-...

Is it right? Is it wrong? What does it mean to even BE a 'face' ?

Although I guess the worst thing that could happen in this situation is you change your explanation of the tattoo, and not the tattoo itself.