Comment by DrJokepu
10 hours ago
> 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.
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".
I recall my old chemistry/physics teacher doing it too - "now THIS guy, he's really greedy for electrons" and stuff like that.
Maybe they're French? They tend to do that, translating celui