# Difference between revisions of "Talk:1724: Proofs"

Judging from my experience when I first encountered proofs in math classes (or my general experience from math classes), the teacher is going to write down a "proof" which makes absolutely no sense to students and is also never explained in a way that actually makes them understand. Instead, they are just going to use "dark magic" and write what seems to be completely senseless to students. 141.101.91.223 04:24, 24 August 2016 (UTC)

'Dark magic' might also refer to the supernatural, so when the teacher said that an answer 'will be written' in a specific location, Cueball took this to mean that a spirit would be summoned to write it, like a ouija chalk board. 141.101.70.67 09:27, 25 August 2016 (UTC)

Transcript generated by the BOT was murdering me, had to change it. Proposing miss Lenhart is party 1. EppOch (talk) 04:45, 24 August 2016 (UTC)

I support that. 141.101.91.223 06:13, 24 August 2016 (UTC)
Me to, but I am on mobile, so editing is a pain 162.158.86.71 06:51, 24 August 2016 (UTC)
Done Elektrizikekswerk (talk) 08:26, 24 August 2016 (UTC)
Note that the BOT doesn't create any text - see here. The transcript was made by several people. Agree completely that this is Miss Lenhart, but even if it was not "party 1 and party 2" is not the way to describe a woman with long blonde hair and Cueball ;-) There is at the moment a discussion what to call other women looking like this (i.e. those that are not clearly Miss Lenhart, Mrs. Roberts or her daughter Elaine Roberts). Chip in there if you have any opinions on that regard... --Kynde (talk) 11:01, 24 August 2016 (UTC)

Irrationality proof isn't really a proof by contradiction (it doesn't use double negation elimination). You're showing (exists a,b. ...) -> False by assuming (exists a, b. ...) and showing False, which is implication introduction --162.158.85.105 07:33, 24 August 2016 (UTC)

I'm thinking she's doing one of those proof that write down a formula or function out of nowhere, and proceeds to proof everything with it. 108.162.222.125 08:43, 24 August 2016 (UTC)

This comic reminds me of "divination" rituals, where a magical spirit is summoned to write out an answer. Usually not something as complex as here, but hey, XKCD! --Henke37 (talk) 10:04, 24 August 2016 (UTC)

Man, Reductio ad absurdum never made any logic. If we could assume any thing, why use logic? Oh wait, it has already been covered in XKCD 162.158.49.12 (talk) (please sign your comments with ~~~~)

"Dark magic" proofs are centered around properties of functions, and abstract concepts, rather than manipulating the functions themselves?? 108.162.246.113 11:26, 24 August 2016 (UTC)

My assumptions is that the "Dark Magic" being referred to here is more "A technique that works, though nobody really understands why." [see http://catb.org/jargon/html/B/black-magic.html] In this case, the teacher is setting up a proof in an manner which will lead to the desired goal, but to the student it is exceedingly unobvious as to why one would do it this way, other than "it works" 108.162.219.52 15:30, 24 August 2016 (UTC)

I was thinking that a "dark magic proof" referred to those ridiculous "party trick" proofs like 'proving' that 1 = 0 via some confusing train of logic, and mathematical sleight of hand. 108.162.237.213 (talk) (please sign your comments with ~~~~)