## Funny mathematical terms and statements

For the discussion of math. Duh.

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Hackfleischkannibale
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### Funny mathematical terms and statements

While I was reading the Expospeak Gag entry on tvtropes, I realized that modern math has a lot of 'inverse expospeak' statements - statements using plain language that refer to something only a few experts understand, and are nonsensical to everyone else. Sadly, I'm learning mathematics in Germany and thus don't know any such statements in English, so I couldn't make an entry of this phenomenon. So:
What mathematical terms do you know that mean something entirely different to us than to non-mathematicians?
What mathematical statements do you know that only use plain-talk words, or use plain-talk words way differently than usual?

Fr'instance, translating the German meaning into english, we get that "every normal family is retarded" (the German word for "bounded", "beschränkt" can be used to insult someone as stupid or retarded), or that the p-adic rationals are completely incoherent ("unzusammenhängend" translates as either "disjointed" or "incoherent").
If this sentence makes no sense to you, why don't you just change a pig?

gfauxpas
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### Re: Funny mathematical terms and statements

Inductive reasoning - statements that are "probably true". They're not based on the deductive method and therefore are about as strong as a "wild guess" in math.

Induction - a form of mathematical proof about the properties of natural numbers. It is an example of deductive reasoning.

NathanielJ
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### Re: Funny mathematical terms and statements

Homepage: http://www.njohnston.ca
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z4lis
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### Re: Funny mathematical terms and statements

Normal Person: Would you like the window open or closed?

Mathematician: Yes.
What they (mathematicians) define as interesting depends on their particular field of study; mathematical anaylsts find pain and extreme confusion interesting, whereas geometers are interested in beauty.

gmalivuk
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### Re: Funny mathematical terms and statements

z4lis wrote:Normal Person: Would you like the window open or closed?

Mathematician: Yes.
This is only potentially ambiguous in writing. When speaking, the difference between exclusive and inclusive "or" is apparent from intonation.
---
Examples that come to mind are "compact", "real", "imaginary", "complex", and "normal".
Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.
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Timefly
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### Re: Funny mathematical terms and statements

The statement "almost all".

korona
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### Re: Funny mathematical terms and statements

In the theory of buildings: apartments, chambers, walls, panels and galleries.

t1mm01994
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### Re: Funny mathematical terms and statements

gmalivuk wrote:
z4lis wrote:Normal Person: Would you like the window open or closed?

Mathematician: Yes.
This is only potentially ambiguous in writing. When speaking, the difference between exclusive and inclusive "or" is apparent from intonation.

I don't think "or" is ambiguous that often.. Usually people replying "yes" to questions involving "or" are just being dbags.

gmalivuk
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### Re: Funny mathematical terms and statements

Well it's not generally ambiguous because people tend to assume exclusive or, that being the more common one in speaking (and the only one worth using in speaking when discussing a situation with literally only two options, like a window being open or closed). But intonation clears up even those situations where both interpretations might work, such as, "Are you free on Saturday or Sunday?"

If my tone goes up on "Saturday" and down on "Sunday", the "or" is exclusive (and I'm furthermore implicitly assuming that you are free on at least one of those days).
If my tone goes up through the whole phrase "Saturday or Sunday", the "or" is inclusive, and I'm asking a yes/no question about whether you're free this weekend.
Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.
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mfb
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### Re: Funny mathematical terms and statements

"Every fields is a ring."

"This forest consists of one tree."

"You cannot 'complete' a rational function [with non-trivial denominator] to get an entire function."

>> Well it's not generally ambiguous because people tend to assume exclusive or, that being the more common one in speaking
Even for an exclusive or, "yes" is a mathematical good answer. He (prefers an open window XOR prefers a closed window).

gmalivuk
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### Re: Funny mathematical terms and statements

But even mathematicians aren't that stupid about how language works. You never get one saying just "yes" to, "Is this integer even or odd?" unless they're trying to be an asshole.
Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.
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gfauxpas
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### Re: Funny mathematical terms and statements

The window question can be answered "yes" whether or not it's an excusive or or not. He's not asking "is the windows open or closed" He's asking "do you want the window open or closed?"

Answer version 1: yes, I would like the window open ∨ closed
Answer version 2: yes, I would like the window (open ∨ closed) ∧ ¬(open ∧ closed)

Meteoric
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### Re: Funny mathematical terms and statements

gmalivuk wrote:But even mathematicians aren't that stupid about how language works. You never get one saying just "yes" to, "Is this integer even or odd?" unless they're trying to be an asshole.

I sometimes say things like that to students trying to get me to tell them the answer (and then ask some questions of my own that will help lead them to find the answer themselves). I guess maybe I'm being an asshole when I do so, but I'm not trying to be an asshole
No, even in theory, you cannot build a rocket more massive than the visible universe.

elseif
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### Re: Funny mathematical terms and statements

My personal favorite (an actual example from the book "Inner Models and Large Cardinals"):

Thus, proving the full iterability of a premouse merely amounts to proving its coiterability with a universal weasel.

Proginoskes
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### Re: Funny mathematical terms and statements

The word "theory" means something different to creationists idiots.

z4lis
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### Re: Funny mathematical terms and statements

gmalivuk wrote:
z4lis wrote:Normal Person: Would you like the window open or closed?

Mathematician: Yes.
This is only potentially ambiguous in writing. When speaking, the difference between exclusive and inclusive "or" is apparent from intonation.
---
Examples that come to mind are "compact", "real", "imaginary", "complex", and "normal".

Well, that's sort of the joke. The words "open" and "closed" are typically exclusive, so the response of "yes" to that question only makes sense if you're being an ass. Perhaps I should have used "topologist" rather than "mathematician".
What they (mathematicians) define as interesting depends on their particular field of study; mathematical anaylsts find pain and extreme confusion interesting, whereas geometers are interested in beauty.

fishfry
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### Re: Funny mathematical terms and statements

korona wrote:In the theory of buildings: apartments, chambers, walls, panels and galleries.

Uh ... would those be Tits buildings?

http://en.wikipedia.org/wiki/Jacques_Tits

Afif_D
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### Re: Funny mathematical terms and statements

Well i always wondered if the eccentricity of a conic has got to do something with madness

skeptical scientist
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### Re: Funny mathematical terms and statements

t1mm01994 wrote:I don't think "or" is ambiguous that often.. Usually people replying "yes" to questions involving "or" are just being dbags.

Or are using "yes" to mean "both", which is also common, at least in my circle. For example, if gmal asked me his "are you free Saturday or Sunday?" question, using intonation to suggest exclusive or, I would answer "yes", and expect him to understand that I meant I was free both days.

My understanding of the joke was that was happening here, and the mathematician wanted the window clopen.

On a somewhat related note, I find the term door space amusing.
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"With math, all things are possible." —Rebecca Watson

vilidice
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### Re: Funny mathematical terms and statements

Integral
Normal use: "That's an integral part..." or if talking about a kingdom "That's an integral domain for..."

Mathematical use: "The integral of the function..." or, "The integral domain X ..."

Derivative
Normal use: "The derivatives market, ... " or "That's so derivative..."

Differentiate
Normal use: "It's hard to differentiate the two, ... "
Mathematical use: "It's hard to differentiate the two ..."

Matrix
Normal use: "The Matrix, derivative of ..."
Mathematical use "The matrix derivative of..."

Projection:
Normal use: "The projection is out of focus."
Mathematical use: "The projection of a vector results in a loss of information."

Function:
Normal use: "The function of the derivative ..."
Mathematical use: "The derivative of the function ..."

etc.

Sagekilla
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### Re: Funny mathematical terms and statements

vilidice wrote:What about the obvious ones:

Differentiate
Normal use: "It's hard to differentiate the two, ... "
Mathematical use: "It's hard to differentiate the two ..."

I'd argue it's quite easy to differentiate the two It's just a constant (zero)!
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antonfire
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### Re: Funny mathematical terms and statements

When you put something in some sort of "normal form", you are actually putting it into a very specific form.
Jerry Bona wrote:The Axiom of Choice is obviously true; the Well Ordering Principle is obviously false; and who can tell about Zorn's Lemma?