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rnhmjojtoday at 5:47 AM5 repliesview on HN

> My concern is that the word “elementary” in the title carries a much broader meaning in standard mathematical usage, and in this meaning, the paper’s title does not hold.

> Elementary functions typically include arbitrary polynomial roots, and EML terms cannot express them.

If you take a real analysis class, the elementary functions will be defined exactly as the author of the EML paper does.

I've actually just learnt that some consider roots of arbitrary polynomials being part of the elementary functions before, but I'm a physicist and only ever took some undergraduate mathematics classes. Nonetheless, calling these elementary feels a bit of stretch considering that the word literally means basic stuff, something that a beginner will learn first.


Replies

SideQuarktoday at 11:35 AM

> If you take a real analysis class, the elementary functions will be defined exactly as the author of the EML paper does.

I just looked through many of the best known real analysis texts, and not a single one defines them this way. This list included the texts by

Royden, Terence Tao, Rudin, Spivak, Bartle & Sherbert, Pugh, and a few others....

Can you cite a single text book that has this definition you claim is in every real analysis course? I find all evidence points to the opposite.

burnishedtoday at 6:23 AM

All I know is that when a class starts with 'elementary' or 'fundamentals of' you had best buckle up.

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reikonomushatoday at 5:56 AM

The definition of "elementary function" typically includes functions which solve polynomials, like the Bring radical. The definition was developed and is most fitting in algebraic contexts where algebraic structure is meaningful, like Liouvillian structure theorems, algorithmic integration, and computer algebra. See e.g.

- Page 2 and the following example of https://billcookmath.com/courses/math4010-spring2016/math401... (2016)

- Ritt's Integration in Finite Terms: Liouville's Theory of Elementary Methods (1948)

It's not frequent that analysis books will define the class of elementary functions rigorously, but instead refer to examples of them informally.

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chiitoday at 7:04 AM

jargon are words being used that don't carry the typical laymen definition, but a specific one from the domain of said jargon.

If a written piece is intended for an audience who knows the jargon, then it's fine to use jargon - in fact it's appropriate and succinct. If it was intended for the laymen, then jargon is inappropriate.

But it seems you're lamenting that this jargon is wrong and that it shouldn't be jargon!?

mcmoortoday at 7:22 AM

I don't know if I read this right, but I thought it's proven that "elementary functions" can't solve 5th degree or higher polynomial, so I'm confused how it's interpreted if elementary functions also include arbitrary polynomial roots. Or is it different elementary functions?

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