How do you end your proofs? QED, box, ...

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How do you end your proofs?

QED
87
41%
Open Box
48
23%
Filled In Box
31
15%
WWWWW or W^5
8
4%
Other
39
18%
 
Total votes: 213

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How do you end your proofs? QED, box, ...

Postby mudge » Sun Oct 28, 2007 8:54 am UTC

In the vein of W^5 (or WWWWW = "Which Was What We Wanted") I'm trying to get "BB" popularized.

BB for "Badabing"

Seriously, next time you're telling somebody a proof, when you get to the end, just say "badabing" .. it fits so well.
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Re: How do you end your proofs? QED, box, ...

Postby LoopQuantumGravity » Sun Oct 28, 2007 9:00 am UTC

mudge wrote:In the vein of W^5 (or WWWWW = "Which Was What We Wanted") I'm trying to get "BB" popularized.

BB for "Badabing"

Seriously, next time you're telling somebody a proof, when you get to the end, just say "badabing" .. it fits so well.


THE END

I also like to start proofs with "BEHOLD!"
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Re: How do you end your proofs? QED, box, ...

Postby mudge » Sun Oct 28, 2007 9:26 am UTC

LoopQuantumGravity wrote:
mudge wrote:In the vein of W^5 (or WWWWW = "Which Was What We Wanted") I'm trying to get "BB" popularized.

BB for "Badabing"

Seriously, next time you're telling somebody a proof, when you get to the end, just say "badabing" .. it fits so well.


THE END

I also like to start proofs with "BEHOLD!"


haha, nice.

For the really avant garde proofs, do you end with FIN?
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Re: How do you end your proofs? QED, box, ...

Postby Robin S » Sun Oct 28, 2007 1:58 pm UTC

Quite surprised that QED is so unpopular (so far).
This is a placeholder until I think of something more creative to put here.

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Re: How do you end your proofs? QED, box, ...

Postby Gelsamel » Sun Oct 28, 2007 2:16 pm UTC

QED is by far the coolest.
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Re: How do you end your proofs? QED, box, ...

Postby blob » Sun Oct 28, 2007 2:31 pm UTC

"Ok, tea time!"

(Mathematics is thirsty work.)
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Re: How do you end your proofs? QED, box, ...

Postby Mathmagic » Sun Oct 28, 2007 4:15 pm UTC

Gelsamel wrote:QED is by far the coolest.

Word.

What's even better is when you use QEF, and people are like WTF?. :o
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Re: How do you end your proofs? QED, box, ...

Postby GBog » Sun Oct 28, 2007 5:11 pm UTC

For me, it depends on the complexity of the proof. QED has an audacious ring to it, and is constricted to 'surprising' proofs, i.e. proofs which depend on a property that is seemingly unrelated to the claim; and, I'd guess, new proofs, but I haven't written any of them.

For simple, straight-forward proofs, an open box suffices.

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Re: How do you end your proofs? QED, box, ...

Postby xyzzy » Sun Oct 28, 2007 6:02 pm UTC

I use QED.

Edit: I also like to preface that with voilá if the proof involved a surprising step, especially to finish.

So if it's something that is non-obvious until the very end, follow the key point with "And voilá!, [last few lines]. QED"
Last edited by xyzzy on Mon Oct 29, 2007 6:01 pm UTC, edited 1 time in total.
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Re: How do you end your proofs? QED, box, ...

Postby Grincement » Sun Oct 28, 2007 6:12 pm UTC

For someone who will happily admit that I struggle at maths and often have to work up a good brain sweat before reaching the end of a problem , QED is the sweet relief and the knowledge of a job well done.
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Re: How do you end your proofs? QED, box, ...

Postby Marbas » Sun Oct 28, 2007 8:50 pm UTC

TYFC

There's your fucking cookie.

Actually...I just use a box, or random scribble.
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Re: How do you end your proofs? QED, box, ...

Postby Hexadecimator » Mon Oct 29, 2007 5:41 am UTC

Normally just a box, but if it's something difficult or something amazingly cool (eg. seemingly unrelated stuff with a awesome surprise twist at the end) QED is the perfect way to end it with a bang. QED, bitches.
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Re: How do you end your proofs? QED, box, ...

Postby Amicitia » Mon Oct 29, 2007 6:18 am UTC

I light the proof on fire when it's finished.

Or I use a clock-stamp for start and finish. Thank you very much LaTeX.
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Re: How do you end your proofs? QED, box, ...

Postby antonfire » Mon Oct 29, 2007 6:48 am UTC

Usually, I don't really put anything. Sometimes a box. For the particularly special ones, I write "Proven With No Enduring Doubt".
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Re: How do you end your proofs? QED, box, ...

Postby madprocess » Mon Oct 29, 2007 5:57 pm UTC

Granted I'm still an undergrad, so my proofs haven't been difficult or surprising. However, I put a diagonally hashed box at the end. If it's a iff problem, I'll put a half filled diagonally hashed box at the end of each if-then statement and then state my conclusion and follow it with a hashed box.

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Re: How do you end your proofs? QED, box, ...

Postby uselessuser » Mon Oct 29, 2007 10:00 pm UTC

I mostly use boxes. Simple, boring boxes. They always seemed to yell "and if you consider _this_ proof completely random and weird, wait until I you see the one where I left out the few remaining english words as well!". Payback time.

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Re: How do you end your proofs? QED, box, ...

Postby Torn Apart By Dingos » Mon Oct 29, 2007 10:04 pm UTC

Open boxes ftw! I'm surprised QED is so popular. It's not common in books.

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Re: How do you end your proofs? QED, box, ...

Postby of.hippo » Mon Oct 29, 2007 10:10 pm UTC

I usually just do a filled in box, but I used to write "Ta-Da", then it morphed into a ta-da symbol, which quickly became a TIE Fighter. Please draw Star Wars ships at the end of proofs, it makes professors happy.

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Re: How do you end your proofs? QED, box, ...

Postby Archena » Mon Oct 29, 2007 10:54 pm UTC

QED...

In huge letters scrawled over the proof itself... with a black marker.
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Re: How do you end your proofs? QED, box, ...

Postby Nimz » Tue Oct 30, 2007 8:34 am UTC

Although I do like using QED, I actually use an empty box more often. That way I can draw in a smiley face inside it if I get bored. Um, pixel in a smiley face. Hmm I don't think that helped much. :?

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Re: How do you end your proofs? QED, box, ...

Postby Arancaytar » Tue Oct 30, 2007 8:57 am UTC

qed

All lowercase. Although "tea time" and "bada-bing" are both interesting options, and I'll just have to try "Behold!" some time.

For the particularly special ones, I write "Proven With No Enduring Doubt"


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Re: How do you end your proofs? QED, box, ...

Postby crazyjimbo » Tue Oct 30, 2007 9:22 am UTC

I like the box for it's simplicity, yet it oozes loads of raw prooving power. When you put that box, it MEANS something, and that 'spretty powerful for a little box. Perhaps too much for it to handle.

But, there is nothing quite like scrawling QED over half the page when you finally crack a proof that's had you crying, screaming, and suffering for 3 days straight.

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Re: How do you end your proofs? QED, box, ...

Postby LoopQuantumGravity » Tue Oct 30, 2007 9:32 am UTC

of.hippo wrote:I usually just do a filled in box, but I used to write "Ta-Da", then it morphed into a ta-da symbol, which quickly became a TIE Fighter. Please draw Star Wars ships at the end of proofs, it makes professors happy.


I do occasionally call a capital phi "capital tie fighter."
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Re: How do you end your proofs? QED, box, ...

Postby djooleek » Tue Oct 30, 2007 5:56 pm UTC

QED unless it was a proof by contradiction which gets an "RAA!!!!" for reductio ad absurdum.

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Re: How do you end your proofs? QED, box, ...

Postby b.i.o » Wed Oct 31, 2007 2:35 pm UTC

Sometimes a box. For the particularly special ones, I write "Proven With No Enduring Doubt".


:D

I'm definitely doing that next time I have to prove something.

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Re: How do you end your proofs? QED, box, ...

Postby Arancaytar » Wed Oct 31, 2007 2:47 pm UTC

[quote]have to prove something[/url]

...or something to prove. :)
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Re: How do you end your proofs? QED, box, ...

Postby Dongorath » Wed Oct 31, 2007 2:56 pm UTC

CQFD (it's French : "Ce qu'il fallait démontrer", roughly translated to "What was to be demonstrated" or whatever a better translation would be).

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Re: How do you end your proofs? QED, box, ...

Postby CellBlock » Wed Oct 31, 2007 3:43 pm UTC

I'm a fan of QED in other arenas besides math, like finishing up a section of a debate with "QED, bitch."

Back in discrete math, though, I usually just finished up with a derivative of W^5 (something like "which is as stated"), and then a double slash in/beside the right margin. That's what the teacher used, so I just sort of adopted it, and then kept using it later.

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Re: How do you end your proofs? QED, box, ...

Postby ks_physicist » Wed Nov 07, 2007 8:03 am UTC

I am tagging this purely for future reference.

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Re: How do you end your proofs? QED, box, ...

Postby Unakau » Wed Nov 07, 2007 12:39 pm UTC

I like QED. It looks so proffessional.

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Re: How do you end your proofs? QED, box, ...

Postby Foil » Wed Nov 07, 2007 3:50 pm UTC

I'd like to say I use something cool or inventive ("spla-DOW!"), but I just typically use "QED" or sometimes nothing if it's obvious the proof is done.
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Re: How do you end your proofs? QED, box, ...

Postby Spivak » Thu Nov 08, 2007 11:33 am UTC

Usually I don't write the proof at all. I just do the math completely out of order through my notebook, in the end it looks like a total mess.

When I'm serious about it though i use c.q.d. at the end of the proof. It's short for como queríamos demonstrar which is Portuguese for the same thing the french-speaking guy posted.

I'm looking foward to use "Ta-Da" or "Behold!" in my tests :)
Sorry for my bad grammar and my wrong ortography. I'm Brazilian, never left my country and I am too lazy to go to English classes. They bore me :(

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Re: How do you end your proofs? QED, box, ...

Postby ++$_ » Fri Nov 09, 2007 8:08 am UTC

A T.A. of mine suggested ending proofs with "OSB": "Oh snap, bitch."

I use a filled-in box, right-justified. In my notes, I make an empty box instead when the proof is omitted or informal.

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Re: How do you end your proofs? QED, box, ...

Postby Sly Si » Fri Nov 09, 2007 4:31 pm UTC

I usually use the filled-in box by default. When I'm in the mood, though, I use QED. Results that have a surprising twist at the end (i.e. going from something seemingly completely unrelated to the exact thing we want to prove in a line or two) usually get an exclamation point, sometimes a box as well. And when the result is nifty, I use a smiley face.

I also use the smiley face in lecture notes to stand in for "and the rest of the steps are obvious".

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Re: How do you end your proofs? QED, box, ...

Postby MysticTerminator » Sat Nov 10, 2007 10:02 am UTC

"as desired"

I really hate QED. It seems overly pretentious. and also means quantum electrodynamics, so all the mathematical physicists get confused.

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Re: How do you end your proofs? QED, box, ...

Postby maafy6 » Sun Nov 11, 2007 4:03 am UTC

My ACalc professor used a lightning bolt to conclude a proof by contradiction, which I thought was way better than the alternative of ><. When I saw that, though, I wished other proofs had a cool symbol, so I started using a really small tornado, complete with house and Todo for my other proofs. If I get a chance, I'll draw it up in GIMP later and attached it.

Also, my Algebra prof would use a box for proofs, and it would be filled in if all details were provided, something that looked like a mesh if it was mostly there but there were some things missing, and an empty box for a sketch.

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Re: How do you end your proofs? QED, box, ...

Postby the tree » Mon Nov 12, 2007 12:25 am UTC

MysticTerminator wrote:I really hate QED. It seems overly pretentious.
In an effort to become more pretentious I am adopting CQFD instead of QED.

Although having a thing for full sentences and clarity in my writing most of the time I end with "So [thing that I was proving] must hold."

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Re: How do you end your proofs? QED, box, ...

Postby Maurog » Mon Nov 12, 2007 4:15 pm UTC

I always thought the box was an ancient Latin pun based on Quod Erat sounding similar to the latin word/root for "square". I now know it isn't, but it made so much sense!

And still does. If the ancients thought of it, they'd use it for sure.
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Re: How do you end your proofs? QED, box, ...

Postby Kawa » Tue Nov 13, 2007 3:18 am UTC

What, "quod erat demonstratum" doesn't mean "Look, a filled-in box"?! XD

I'm seriously tempted to go the lolcat route and go "kthxbai" after proofs (and starting proofs with "I can has <proof method here>," since my current class has instructions like "Prove this by induction" and "Prove this by contradiction".)
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Re: How do you end your proofs? QED, box, ...

Postby ks_physicist » Tue Nov 13, 2007 3:51 am UTC

Kawa wrote:What, "quod erat demonstratum" doesn't mean "Look, a filled-in box"?! XD

I'm seriously tempted to go the lolcat route and go "kthxbai" after proofs (and starting proofs with "I can has <proof method here>," since my current class has instructions like "Prove this by induction" and "Prove this by contradiction".)


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I would also like to propose "TAFJ", for "That's A Fact, Jack!"


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