[DrJokepu]

> I recall a math instructor who would occasionally refer to variables (usually represented by intimidating greek letters) as "this guy".

I also had an instructor who was doing that! This was 20 years ago, and I totally forgot about it until I have read your comment. Can’t remember the subject, maybe propositional logic? I wonder if my instructor and your instructor have picked up this habit from the same source.

[kombookcha]

I recall my old chemistry/physics teacher doing it too - "now THIS guy, he's really greedy for electrons" and stuff like that.

[adammarples]

Maybe they're French? They tend to do that, translating celui

[Tyr42]

My instructor for Epsilon Delta proofs and limits would always talk about "his cousin in Romania" picking the Epsilon and him picking the Delta.

i.e. forall epsilon > 0. exists delta > 0. forall d with |d| < delta. |f(x) - f(x+d)| < epsilon.

If we had a proof, no matter what epsilon his cousin from Romania picked, we could always find a new delta which would satify his cousin and let him pick the worst d in range.

This worked better than just saying "pick any epsilon", as it convayed the adversarial approach better.

Another book I read used the Devil as the one you are trying to convince, but it's nowhere near as fun as "his cousin from Romania".