>it's a 'proff takes entire lecture on one

> when you're 20 minutes into a proof and forget what you were trying to prove in the first place

>when the prof makes up new notation and redefines it halfway through the proof

>>8660596
>professor defines notation
>never uses it

>proof requires another proof

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13KB, 236x314px

>professor has to constantly check his notes to reproduce the proof on the board

>>8660580

Amateur move. Freshmen and sophomores go to class.

>>8660629

>professor wrote something down wrong in his notes and can't continue the proof

>>8660619
REEEEEEEE
>And it took half the class to usnerstand it

>>8660580
>Number Theory
>Does not mark the Natural set symbol with a little 0 or 1 that shows with what it starts
>Every single time he gives a problem about natural numbers I have to ask 'In this problem, do the naturals include 0'
>the answer is always yes
>one day it may not be

>>8660671
Fuck that's annoying

>>8660629
>"weeh how to do this freshman shit again??!"

>it's a "proff uses all three lectures to prove one theorem" week

I'm looking at you, structure theorem for finitely generated modules over a PID

>>8660689
I know right.

Every single textbook specifies that naturals start with 1 but with him they start with 0.

But who knows when he catches up with 2017 and realizes that 0 is not a natural number. If I don't ask I could get fucked.

>>8660704
0 is natural number, maybe not for undergraduates but every self respecting mathematican includes 0 on naturals. Set theory constructs 0 first and rest from it.

>>8660735
Most books have it start with 1. What the fuck are you talking about?