Talk:Epsilon

Two varieties of epsilon

At first line of the article the unicode symbol given for epsilon is actually 'LATIN SMALL LETTER OPEN E' (U+025B). It's confusing when one uses this article for copying the letter to eg. computer program where the code matters, not only the shape. — Preceding unsigned comment added by 82.131.27.253 (talk) 12:30, 21 March 2015 (UTC)

In LaTeX there are two epsilon characters: \epsilon and \varepsilon. The variant version is the one described on the page, but there's no mention of LaTeX's normal epsilon character. I know I've always seen \epsilon used for describing set membership, but \varepsilon for describing small numbers. Can someone add more authoritative information explaining the difference in usages? 192.160.6.252 20:00, 10 Mar 2005 (UTC)

I don't know the answer to your question, but I can say that LaTeX's \epsilon, $ϵ$, is different from its set membership symbol, \in, $\in$. —User:Caesura^(t) 14:43, 21 November 2005 (UTC)

I added a short description of the Lunate Espilon. As far as I know, the two are effectively interchangeable, although there might be some deeper distinction between two in more formal usage. Pagasaeus 06:29, 30 November 2006 (UTC)

Maybe it's just my font, but it isn't clear which is the normal epsilon ($\epsilon$?) and which is the lunate epsilon ($ϵ$?); The latter symbol is used almost exclusively in the first paragraph. Since fonts can vary, perhaps a small picture would be helpful. --ScottAlanHill 15:11, 5 March 2007 (UTC)

Right now the article appears to contradict itself. It claims that "The standard symbol for lowercase epsilon is the lunate epsilon", but shows an open one in the infobox image. If the two shapes are indeed interchangeable in ordinary typography (like the open-tail and loop-tail forms of 'g' in Latin script), the article should not claim that one is "standard". Or is it more like the difference between upright and italic Latin 'a'? –Henning Makholm 01:08, 1 January 2008 (UTC)

This currently appears as a contradiction on my screen:

In TeX, \epsilon (ε) denotes the lunate form.

The parenthetical example there (which in the article source is created using TeX code) does not produce the lunate form. The \varepsilon is an obvious, "fancier" variation, but neither produces the lunate (ϵ). Whether a font issue, a TeX implementation issue, or some other problem, we can assume that it appears incorrect to others, as well.

Are we sure that TeX specifies the lunate form for \epsilon? Either way, I'd probably recommend not saying so, at least until we figure out what's up here. /ninly_(talk) 20:13, 31 August 2010 (UTC)

Statistics symbol

Trying to find symbol for nonparametric hypotesis test. It is either Epsilon or Pi. Any ideas? 3.1415926535897932384626433...

Definition

What is the meaning of the first two sentences of the third paragraph: "Epsilon is one the six numbers that fomulate the universe that make the universe suitable for life within the cosmos.The founder of the sixe numvers is Rees J. Martin." ? This seems vague, misspelled and/or simply incorrect or misleading..

Page contradicts itself

From introduction section "The lunate epsilon ϵ is not to be confused with the set symbol ∈." However the Symbol section states "In mathematics, set membership (often written ∈ instead of ε)." I believe that the latter definition should be deleted. The set symbol is NOT an epsilon, it is just a generic mathematical symbol. 220.233.204.250 05:42, 4 August 2007 (UTC)

• I agree; I've removed it. --ScottAlanHill 06:58, 5 August 2007 (UTC)

Epsilon

Epsilon Tekstil ve Çanta üzerine kurulmuş bir firma. 1986 den beri varlar. daha geniş bilgi için: http://www.epsilon.com.tr —Preceding unsigned comment added by 85.96.136.247 (talk) 12:57, 15 June 2009 (UTC)

semi-protected?

SO it says this is semi-protected indefinitely due to high risk of vandalism. There doesn't seem to be any that has happened recently and there is no mention of any on the talk page. Why not lock down every article since someone MIGHT vandalize them too?

Hello?

Looks like no one is looking at your comment. There are some other Greek letters that are locked. There isn't any consistency or reason stated. Looks like the admins that locked it dropped the ball.

Disambiguation?

Rather than the Greek epsilon being favored, and with as many other things (companies, languages, etc.) known simply as "Epsilon", having them all routed through this article doesn't make much sense. With "Epsilon" being a significant news item, it shouldn't be this difficult to discover that nobody has created an entry for the company yet. Merennulli (talk) 17:06, 4 April 2011 (UTC)

I'd like to know why there isn't a disambiguation page somewhere... Epsilon (disambiguation) doesn't exist, and there are so many possible articles. 70.24.248.23 (talk) 11:14, 15 November 2011 (UTC)

External links modified

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Rollback?

Template:U, sorry, I don't understand your Template:Diff. The text (you removed) said nothing about Halmos, only about modern usage. (1) Nowadays, we write x∈X or x∊X to denote that x is element if X; (2) The ∈ (∊) sign derives from Greek epsilon (specifically from its lunate form). Are there any doubts? Sasha1024 (talk) 19:34, 18 September 2020 (UTC)

The main issue was that the Halmos text was being used as a source of a statement that it didn't support. There are a lot of formatting errors too, but those are fixable. In any case, if it's mainly a statement about the "element of" symbol, then it's not so much about the letter epsilon itself. –Deacon Vorbis (carbon • videos) 19:48, 18 September 2020 (UTC)

Template:U, ”the main issue was that the Halmos text was being used” — I am sorry, but what Halmos text are you talking about? There is no reference to any Halmos text in my proposed change. And I consider the statement about the "element of" symbol to be very related, because the "element of" symbol derives from epsilon. Sasha1024 (talk) 13:03, 22 October 2020 (UTC)

Apparently someone else added a source to your addition. The source that was added didn't support what you wrote, which was unsourced, so it would need a source to be added at all. –Deacon Vorbis (carbon • videos) 13:21, 22 October 2020 (UTC)

Source for what exactly: for (a) the fact that ∈ (or ∊) is nowadays used as "is element of" or for (b) the fact that nowaday ∈ (and ∊) derives from lunate epsilon? (I thought both are obvious, but maybe can provide sources for both of them.) (BTW, did you notice that no entries in that list contain sources?) Sasha1024 (talk) 10:49, 23 October 2020 (UTC) Pinging Template:U. Sasha1024 (talk) 08:32, 26 October 2020 (UTC)

Pronunciation

Article specifies 2 different pronunciations (US, UK) citing Oxford English Dictionary for the UK variant. However, following the citation link confirms the US pronunciation while it does not confirm the UK variant provided in the article. The US variant matches the original Greek while the UK variant seems to be unsupported. 192.234.149.250 (talk) 17:18, 9 May 2025 (UTC)

Agreed. If somebody can write IPA in Wikipedia style, this page at the OED says Template:Nobreak and Template:Nobreak. --𝕁𝕄𝔽 (talk) 22:39, 10 May 2025 (UTC)