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Talk:Metric (mathematics)

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95: 85: 64: 33: 2821: 1259:. This function satisfies the triangle inequality but is non-symmetric: rising the elevator always costs a lot of energy, but lowering it should cost less, or zero, or maybe we can even obtain energy from that operation. The important thing is that we can't obtain energy from travelling a closed cycle. So the relevant positivity axiom is 2877:, have length 12 and are the shortest path between the two points. The current description doesn't seem to mention anything about the taxicab metric that is actually important. However I'm hesitant to edit it since it's been there for so long without anybody noticing. Is there an important reason why it's like this? 2536:, first paragraph , if y is between z and x on the real number line, then d(x,y)≤max(d(x,z),d(z,y)) seems like the correct version. However due to my naivety with Maths, I have not made any changes to ether page concerning this. Regardless, I believe that one of the two pages is wrong concerning this. 234:
By the way, as one side-note, we would call this a non-negative real-valued function, not a positive definite function. The term positive definite is a linear algebra term for matrices; providing that distinction and link sends the reader off on a very unclearly connected idea. Let's just keep this
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is a metric whenever, for any subset of three points or less, it is the case there is a subset of Euclidean space of the same size that yields the same pairwise distances." (Your input here would be much appreciated.) And as to #2, you are absolutely right; I will look through my textbooks for the
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As it currently reads in Knowledge, the distance induced by a quasi-norm is a semi-metric, and a distance induced by a semi-norm is a quasi-metric. This is confusing, and something should be done to fix this. Whatever the solution is, it should be consistent between generalized norms and generalized
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It becomes important when you consider certain subsets of the axioms; for many such subsets there are names. Positive definiteness is even specifically mentioned in the article. Also in some axiomatisations non-negativity is built in even before the first axiom is mentioned, by saying that "a metric
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is PlanetMath. PlanetMath does not give a reference at all. The presyllable "hemi" is usually used as a synonym for "semi". The concept itself is often referred to as pseudo-quasi-metric, which is a bit longer but logical once pseudometric and quasimetric have been defined. Google has 852 hits. Some
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I think both of you are emphasizing different important ideas. As presently stated, it is NOT mathematically elegant (and actually inaccurate) to claim that all three axioms are responsible for the result that distinct points have positive distances. Here is why: Because the function is defined to
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You need (1) to make clear the relevance of what you are talking about to distance functions, rather than to Euclidean spaces (a different thing, and not the topic of this article), and (2) to back up all claims in whatever you add by reliable published sources. Also, obviously (3) to say something
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is Arkhangelskii and Pontryagin: General Topology I. My library doesn't have the book, and it's not on Google books either, therefore I can't check that the strange word "prametric" really appears in the book. Google has 1660 hits for it. Each of the first 100 hits is either an obvious misspelling
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The first sentence in the definition of the metric explains about the range being positive, immediately explaining that 'distance' can't be negative. Then, property 1 of a metric says it's positive, which is actually specifying its range again. And then it says that non-negativity follows from the
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are the same. We have two separate articles for these topics. Is the lead correct? If that's the case, then these articles should be merged. Is metric tensor applied more typically in the context of differentiable manifolds, whereas metric is the more general concept, used usually in discrete
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A little update: I checked the definition with a book I'm using at my university (not a definitive resource as it is printed locally) and it states that there are three 'axioms of a metric' (identical to axioms 2, 3 and 4 here on wikipedia) and that nonnegativity follows from them (apparently all
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That said, what it SEEMS that one of you is trying to say is that if d were defined as a real-valued function without the non-negative range restriction, then all three axioms together would imply the positive criteria. I'm going to make a change to this effect to see if we can't make both
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How does the Minkowski metric fit in? It is called a metric on Minkowski space, but it does not appear to satisfy any of the definitions in this article. Each of the special flavors (pseudometrics, quasimetrics, metametrics, semimetrics, premetrics) include semi-positive definiteness
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of them are for "m-hemimetric", whatever that is, and I suspect that many are variants for "semimetric". Google Scholar has 0 hits. Google Books has 2 hits: One for "m-hemi-metric", and one for "quasi-hemi-metric", a combination that makes no sense with our definition.
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The comment you supplied when reverting my edit is confusing to me, which leads me to the belief that my edit to the article was confusing to the reader. I will try for more clarity with my next attempt. Thank you for looking out for the quality of Knowledge.
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for "parametric", or it's on Knowledge or a clone. Google Scholar has 94 hits, every single one is an obvious misspelling for "parametric". Google books has, surprise, one relevant hit among 25 misspellings: Ruben Aldrovandi and J. G. Pereira,
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I see two problems here: a missing comma before "which", and ambiguity as to which noun phrase it qualifies. (It is intended to refer back to the "structure" mentioned.) Definitely needs rephrasing to avoid the ambiguity. I have done so. —
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Since all combinations of the axioms can be expressed by combinations of pseudo-, semi- and quasi-, there is no reason why Knowledge should coin a strange new term such as "prametric". (Or help the translator of a Russian book to do so.)
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The word "induce" is used on this and several related pages. Does this have some specific technical meaning? Is it related to the word "induction" in logic? Or is it perhaps a synonym for "implies", or just "results in" or ????
726:. May be his intentions were good, but now the articles create a confusing mess rather than a coherent mathematical discourse. Please someone can initiate a microproject to put some order/system into this topic? `' 2381:
Not logical induction. In a mathematical context it seems to mean "implies the existence of". Or more informally, "produces". Though I don't see this precise meaning in the online dictionaries that I browsed. —
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Apparently d(x,x) = 0 is also required, although it's not stated explicitly. Thus the notion is identical with that of pseudoquasimetric or hemimetric, already discussed further down in its own section.
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I think that splitting was perhaps unfortunate, or could have been done better, as witness the section asking for synchronisation of content. I would suggest that if articles are spilt there should be:
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I think this splitting up is a good idea, but more cross-links are needed between these two pages (and they should refer to precise sections and/or examples, so section titles should be well-thought).
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The notion of 'metric induced by a norm' is already used 2 sections before(Examples) so there should be at least a forward reference (maybe better give the definition in a subsection of "examples")
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Correct me if I'm wrong but I believe that the first condition in the definition is redundant as it follows from identity of indiscernibles (condition 2) and triangle inequality (condition 4)
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Section linking between articles is a very bad idea, because the links are prone to breaking. If section linking cannot be avoided the two articles should be merged again. What do you mean by
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User:Valandil211 started changing html to inline TeX in the article. I strongly believe that there is no consensus for it, and I'd like to get some support to tell him to stop doing this. --
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Misnomer: The condition that is relaxed in comparison to quasimetrics is positive definiteness, not positivity. Positivity, at least as used in this article, just says that d(x,y) : -->
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I guess the maximum that we need here is a mention that someone has called pseudoquasimetrics non-positive quasimetrics and maybe a link to the book for an example of such a thing.
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To show that mathematicians have used the term quasi-metric to refer either to a lack of symmetry, or to a relaxed triangle inequality, a brief search provides the following papers
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Why keep it if it's redundant? Perhaps it would be better style to keep 2-4 as axiom and remark that nonnegativity follows from them (i. e. is not an axiom but a useful property).
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below. my private opinion: non negativity is too fundamental to not mention it (and later the other axioms are removed), ps next time add new sections yat the end of the page  :)
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That is a misreading. They are not the same, and should not be merged. In particular, there are many examples of metrics and metric spaces that do not come from a metric tensor. —
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A clear indication at the beginning of each article which other article(s) there are, and of what content can be found where, consistent with the principle guiding the split.
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be non-negative, d(x,y) can only be zero or positive. Now, axiom 1 rules-out distinct points being 0, thus forcing their distance to be positive--without axioms 2 & 3.
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are probably from me. I had intended to do a cleanup in the next few days. All your suggestions seem reasonable so go ahead. However I would keep the old section title
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Perhaps some people who actually work in topology and functional analysis, or in related disciplines, can check whether the passages about the two definitions of
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really describe usage in their respective fields. I have also asked the MSC2010 group to clarify what the MSC2000 category "54E25 Semimetric spaces" is about. --
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As a sidenote, I think it is uneccessary to discuss such small modifications on the talk page. The next time you should be more bold and just do the changes.
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It's easy to prove 1 from 2-4 (and an easy counterexample with two points shows just 2 and 4 are not enough). But this doesn't mean we need to drop 1. --
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This claims that a differential manifold is more properly termed a metric tensor. I suspect "which is" was intended to refer back to the structure.
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So that's a total of two books defining the term. (The book on Google Books doesn't seem to do anything with it except that it derives a topology.)
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in "Definition", it is written "function function" - should we just delete the first "function", or was it intended to replace it with "distance" ?
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To be absolutely sure, I made a number of searches in publications. Numbers are for search without hypen/with hyphen, e.g. prametric/pra-metric.
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Perhaps: "...used to refer to a structure defined only on a differentiable manifold. Such a structure is more properly termed a metric tensor"
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In the case of this particular split I suppose the principle could be that variants on the concept and properties of the function go in
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Does anybody know how a Minkowsky space would fit in here? It seems that it drops 1,2, and 4 but I never found a mathematical name.
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coefficent to a specific geometric series. That's what's in my book, and I guess it's needed to ensure convergence of this sum -
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No more overlap between them than is necessary to make the individual articles readable without excessive jumping back and forth.
1724: 772:. Most people are reluctant to remove something just because they have never heard of it. So am I, but this was a special case. 3060: 2918: 2869:, and is the unique shortest path.” This is misleading, because the red, yellow and blue paths have the same length in taxicab 2635:
The article mentions offhand, in the section on quasimetrics, that the quasimetric inducing the Sorgenfrey Line may defined as
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Section links need not get broken if you add anchors to the sections, and if people realise the implications of the anchors :(
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1) refers to a property "5" which is not defined ; please correct (and, if possible in 1 or 2 lines, write the proof).
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I think these results show clearly that it is seriously misleading to direct unsuspecting readers to the articles on
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to the Euclidean metric on the plane: According to the taxicab metric the red, yellow, and blue paths have the same
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An easily formulated principle enabling an editor to decide which content belongs where, perhaps in an HTML comment.
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I suggest that at least "pseudo" and "ultra" should be defined in the same place than "intrinsic" (much more used,
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spaces? In other words, is there a distinction here, which should be pointed out? If not, why not merge?
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I am not fundamentally opposed, I just don't think it would be a clear improvement to drop the axiom. --
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on Knowledge. If you would like to participate, please visit the project page, where you can join
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The picture right on the top of the page has this description: “An illustration comparing the
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at zero cost by doing nothing). The most similar concept described in this article is that of
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that is meaningful and correct mathematically. None of 1,2,3 was evident in what you added. —
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three). I will try to research this further but I have limited access to sources in English.
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The example is excessive compared to the other equally or more important generalisations.
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The added value (#1 and #3) was supposed to be an easier to read version of: a function
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Fixed point theorems in generalizing spaces of quasi-metric family and applications
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I also agree that there is no consensus, and I strongly prefer the inline TeX.
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seem sort of arbitrary and bewildering; does anyone have a source for them?
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I think this new material is not appropriate, at least in the present form:
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Quasi-Metric Spaces, Quasi-Metric Hyperspaces and Uniform Local Compactness
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I agree that there is no consensus, and I don't agree with the change. --
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The real number line is a metric space, but not an ultrametric space. —
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is a metric (aka a distance function) if and only if for every subset
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The only frequently used terms for generalized metrics appear to be:
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as saying a non-negative function. Dr. Belnap 15:49, 7 May 2021 (UTC)
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be the space of possible states of a certain machine (for example,
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is the usual Euclidean distance function. Maybe I can say that "
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See my simultaneous contribution to the section on the split.
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be the infimum energy needed to take the machine from state
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source. (Your input here would also be much appreciated.) —
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Terminology is inconsistent with semi-norms and quasi-norms
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Euclidean metric as the motivation for metrics generally
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A new approach to function spaces on quasi-metric spaces
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but that this 1 may be replaced with infinity or with
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The taxicab×Euclidean figure has a misleading caption
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Fixed Point Results in Dislocated Quasi Metric Spaces
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as it is more common in math articles on wikipedia.
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metric space (depending of course on how one defines
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And it is non-symmetric, in fact, whenever 8: 2471:Quasi-metric properties of complexity spaces 1857:of the durations of all possible trips from 1151: 1127: 289:different metrics can be used to define the 2594: 2534:https://en.wikipedia.org/Ultrametric_space 58: 2846: 2841: 2765: 2723: 2711: 2678: 2666: 2226: 2191: 2156: 2079: 2053: 2043: 2030: 2014: 2004: 1991: 1982: 1980: 1956: 1943: 1927: 1921: 1897: 1884: 1868: 1862: 1834: 1821: 1809: 1786: 1776: 1763: 1754: 1745: 1732: 1726: 1702: 1689: 1673: 1667: 1643: 1630: 1614: 1608: 1528: 1472: 1431: 1407: 1387: 1346: 1305: 1264: 1244: 1224: 1189: 1169: 1119: 1099: 648: 615: 608: 600: 591: 585: 574: 547: 43:does not require a rating on Knowledge's 2862:{\displaystyle 6{\sqrt {2}}\approx 8.49} 2819: 2631:Quasimetric inducing the Sorgenfrey Line 2144:{\displaystyle s(x,z)\geq s(x,y)+s(y,z)} 1603:Notice that if you can go from an event 828: 177:others. Sounds a bit superfluous to me. 1523:I added a reference for only requiring 783:An Introduction to Geometrical Physics. 193: 60: 2875:including and especially the green one 2489:On completeness in quasi-metric spaces 2406:= 0 for all x,y. This actually holds. 2397:New section Non-positive quasimetrics 391:Also (redundantly) a reference under 106:This redirect is within the scope of 30: 7: 1094:Consider the following example: Let 809:— though very often in the sense of 3079:Redirect-Class mathematics articles 2460:Quasi-metrics as lacking symmetry: 1968:{\displaystyle e_{1}=(t_{1},x_{1})} 1909:{\displaystyle e_{0}=(t_{0},x_{0})} 1714:{\displaystyle e_{1}=(t_{1},x_{1})} 1655:{\displaystyle e_{0}=(t_{0},x_{0})} 460:I recently split this article from 49:It is of interest to the following 3084:High-priority mathematics articles 1157:{\displaystyle X=\{0,\dots ,n-1\}} 950:PS: I was drawn into this because 586: 25: 2584:The lead paragraph suggests that 404:while properties of spaces go in 126:Knowledge:WikiProject Mathematics 2361:"induce" -- what does that mean? 315:, "the same" should mean equal, 146:This redirect has been rated as 129:Template:WikiProject Mathematics 93: 83: 62: 31: 2275:) 12:48, 20 April 2009 (UTC) -- 756:I have made several changes in 424:bug fixes and cleanup suggested 2782: 2770: 2736: 2724: 2691: 2679: 2442:Quasi-metric and metric spaces 2208: 2196: 2173: 2161: 2138: 2126: 2117: 2105: 2096: 2084: 2050: 2023: 2011: 1984: 1962: 1936: 1903: 1877: 1846:{\displaystyle s(e_{0},e_{1})} 1840: 1814: 1783: 1756: 1708: 1682: 1649: 1623: 1545: 1533: 1489: 1477: 1448: 1436: 1363: 1351: 1322: 1310: 1300:(which of course implies that 1281: 1269: 1206: 1194: 666: 654: 633: 621: 564: 552: 1: 2625:20:01, 28 February 2016 (UTC) 2609:18:15, 28 February 2016 (UTC) 2574:02:33, 11 December 2014 (UTC) 2557:02:30, 11 December 2014 (UTC) 2501:A note on quasi-metric spaces 2421:20:50, 12 February 2013 (UTC) 2320:Clarification needed in intro 2221:are defined, it follows that 1574:19:39, 12 February 2013 (UTC) 972:03:01, 22 November 2007 (UTC) 946:02:56, 22 November 2007 (UTC) 788:The only reference given for 776:The only reference given for 120:and see a list of open tasks. 2887:09:26, 14 January 2020 (UTC) 2811:12:30, 26 October 2019 (UTC) 2794:{\displaystyle d(x,y)\geq 0} 2744:{\displaystyle 1+10^{(y-x)}} 2699:{\displaystyle 1+10^{(y-x)}} 2523:21:14, 1 December 2014 (UTC) 2257:19:42, 28 January 2013 (UTC) 2073:reversed triangle inequality 1557:{\displaystyle d(x,x)\geq 0} 1518:19:07, 28 January 2013 (UTC) 1460:{\displaystyle d(x,y)\geq 0} 1375:{\displaystyle d(x,x)\leq 0} 1293:{\displaystyle d(x,x)\geq 0} 3065:19:49, 11 August 2021 (UTC) 2939:16:30, 11 August 2021 (UTC) 2923:12:40, 11 August 2021 (UTC) 1597:22:11, 5 October 2009 (UTC) 731:17:48, 8 October 2007 (UTC) 702:05:49, July 11, 2005 (UTC) 276:article has become too long 3100: 2391:23:13, 4 August 2012 (UTC) 2376:21:48, 4 August 2012 (UTC) 2355:23:03, 4 August 2012 (UTC) 2340:21:07, 4 August 2012 (UTC) 2314:20:36, 20 April 2009 (UTC) 2300:14:38, 20 April 2009 (UTC) 2285:17:36, 20 April 2009 (UTC) 746:19:32, 11 March 2012 (UTC) 446: 418:19:32, 11 March 2012 (UTC) 368:19:32, 11 March 2012 (UTC) 330: 2528:Definition of Ultrametric 2071:. Separation satisfies a 1341:, since it is clear that 479:13:27, 19 Apr 2005 (UTC) 355:13:44, 19 Apr 2005 (UTC) 286:are separate articles too 206:11:19, 8 March 2016 (UTC) 187:08:15, 8 March 2016 (UTC) 145: 78: 57: 2580:Metric and metric tensor 1501:{\displaystyle d(x,x)=0} 1334:{\displaystyle d(x,x)=0} 1084:11:51, 14 May 2008 (UTC) 1039:06:41, 14 May 2008 (UTC) 1021:23:38, 13 May 2008 (UTC) 1006:20:52, 13 May 2008 (UTC) 991:20:36, 13 May 2008 (UTC) 457:12:59, 19 Apr 2005 (UTC) 395:to the related articles. 341:13:28, 19 Apr 2005 (UTC) 304:12:27, 8 Apr 2005 (UTC) 152:project's priority scale 1382:because we can go from 436:), i.e. in "Definition" 109:WikiProject Mathematics 2863: 2825: 2795: 2745: 2700: 2507:On quasi-metric spaces 2483:Weighted quasi-metrics 2241: 2215: 2214:{\displaystyle s(y,x)} 2180: 2179:{\displaystyle s(x,y)} 2145: 2065: 1969: 1910: 1847: 1798: 1715: 1656: 1558: 1502: 1461: 1426:, but it does require 1416: 1396: 1376: 1335: 1294: 1253: 1233: 1213: 1212:{\displaystyle d(x,y)} 1178: 1158: 1108: 676: 590: 349:same should mean equal 2864: 2823: 2796: 2746: 2701: 2242: 2216: 2181: 2146: 2066: 1970: 1911: 1848: 1804:), then the interval 1799: 1716: 1657: 1559: 1503: 1462: 1417: 1397: 1377: 1336: 1295: 1254: 1234: 1214: 1179: 1159: 1109: 724:decided to split them 677: 570: 2990:it is the case that 2840: 2764: 2710: 2665: 2225: 2190: 2155: 2078: 1979: 1920: 1861: 1808: 1725: 1666: 1607: 1527: 1471: 1430: 1406: 1386: 1345: 1304: 1263: 1243: 1223: 1188: 1168: 1118: 1098: 712:Metric (mathematics) 706:Content syncronizing 546: 402:Metric (mathematics) 263:metric (mathematics) 248:metric (mathematics) 132:mathematics articles 18:Talk:Prametric space 2824:This is the figure. 2240:{\displaystyle x=y} 956:praclosure operator 952:preclosure operator 752:Generalized metrics 284:normed vector space 225:distinctions clear. 194:#Axioms of a metric 2979:such that for all 2968:injective function 2859: 2826: 2791: 2741: 2696: 2237: 2211: 2176: 2141: 2061: 1965: 1906: 1843: 1794: 1711: 1652: 1554: 1498: 1457: 1412: 1392: 1372: 1331: 1290: 1249: 1229: 1209: 1174: 1154: 1104: 977:Axioms of a metric 958:and had a link to 954:was misspelled as 685:so I changed that 672: 280:norm (mathematics) 101:Mathematics portal 45:content assessment 2851: 2611: 2599:comment added by 2560: 2543:comment added by 2059: 1792: 1587:comment added by 1415:{\displaystyle x} 1395:{\displaystyle x} 1252:{\displaystyle y} 1232:{\displaystyle x} 1177:{\displaystyle n} 1107:{\displaystyle X} 919: 918: 670: 606: 325:topological space 166: 165: 162: 161: 158: 157: 16:(Redirected from 3091: 3052: 3040: 3029: 2989: 2978: 2966:there exists an 2965: 2963: 2957: 2953: 2910: 2902: 2868: 2866: 2865: 2860: 2852: 2847: 2803:Klaas van Aarsen 2800: 2798: 2797: 2792: 2755:Minkowski Metric 2750: 2748: 2747: 2742: 2740: 2739: 2705: 2703: 2702: 2697: 2695: 2694: 2559: 2537: 2246: 2244: 2243: 2238: 2220: 2218: 2217: 2212: 2185: 2183: 2182: 2177: 2150: 2148: 2147: 2142: 2070: 2068: 2067: 2062: 2060: 2058: 2057: 2048: 2047: 2035: 2034: 2019: 2018: 2009: 2008: 1996: 1995: 1983: 1974: 1972: 1971: 1966: 1961: 1960: 1948: 1947: 1932: 1931: 1915: 1913: 1912: 1907: 1902: 1901: 1889: 1888: 1873: 1872: 1852: 1850: 1849: 1844: 1839: 1838: 1826: 1825: 1803: 1801: 1800: 1795: 1793: 1791: 1790: 1781: 1780: 1768: 1767: 1755: 1750: 1749: 1737: 1736: 1720: 1718: 1717: 1712: 1707: 1706: 1694: 1693: 1678: 1677: 1661: 1659: 1658: 1653: 1648: 1647: 1635: 1634: 1619: 1618: 1599: 1563: 1561: 1560: 1555: 1507: 1505: 1504: 1499: 1466: 1464: 1463: 1458: 1421: 1419: 1418: 1413: 1401: 1399: 1398: 1393: 1381: 1379: 1378: 1373: 1340: 1338: 1337: 1332: 1299: 1297: 1296: 1291: 1258: 1256: 1255: 1250: 1238: 1236: 1235: 1230: 1218: 1216: 1215: 1210: 1183: 1181: 1180: 1175: 1163: 1161: 1160: 1155: 1113: 1111: 1110: 1105: 829: 681: 679: 678: 673: 671: 669: 653: 652: 636: 620: 619: 609: 607: 605: 604: 592: 589: 584: 323:, i.e. the same 134: 133: 130: 127: 124: 103: 98: 97: 87: 80: 79: 74: 66: 59: 36: 35: 27: 21: 3099: 3098: 3094: 3093: 3092: 3090: 3089: 3088: 3069: 3068: 3048: 3039: 3031: 3011: 2991: 2980: 2970: 2961: 2959: 2955: 2945: 2906: 2896: 2894: 2838: 2837: 2818: 2762: 2761: 2757: 2719: 2708: 2707: 2674: 2663: 2662: 2633: 2582: 2538: 2530: 2428: 2399: 2363: 2322: 2265: 2223: 2222: 2188: 2187: 2153: 2152: 2076: 2075: 2049: 2039: 2026: 2010: 2000: 1987: 1977: 1976: 1952: 1939: 1923: 1918: 1917: 1893: 1880: 1864: 1859: 1858: 1830: 1817: 1806: 1805: 1782: 1772: 1759: 1741: 1728: 1723: 1722: 1698: 1685: 1669: 1664: 1663: 1639: 1626: 1610: 1605: 1604: 1582: 1525: 1524: 1469: 1468: 1428: 1427: 1404: 1403: 1384: 1383: 1343: 1342: 1302: 1301: 1261: 1260: 1241: 1240: 1221: 1220: 1186: 1185: 1166: 1165: 1116: 1115: 1096: 1095: 1070: 979: 960:prametric space 754: 708: 693: 644: 637: 611: 610: 596: 544: 543: 530: 516: 508: 497: 485: 483:remove fraction 464:so most of the 426: 269:. Reasons were 255: 174: 131: 128: 125: 122: 121: 99: 92: 72: 23: 22: 15: 12: 11: 5: 3097: 3095: 3087: 3086: 3081: 3071: 3070: 3035: 3007: 2942: 2941: 2931:David Eppstein 2899:David Eppstein 2893: 2890: 2858: 2855: 2850: 2845: 2830:taxicab metric 2817: 2814: 2790: 2787: 2784: 2781: 2778: 2775: 2772: 2769: 2756: 2753: 2738: 2735: 2732: 2729: 2726: 2722: 2718: 2715: 2693: 2690: 2687: 2684: 2681: 2677: 2673: 2670: 2659: 2658: 2632: 2629: 2628: 2627: 2617:David Eppstein 2601:70.247.173.205 2581: 2578: 2577: 2576: 2566:David Eppstein 2529: 2526: 2511: 2510: 2504: 2498: 2492: 2486: 2480: 2474: 2468: 2458: 2457: 2451: 2445: 2427: 2424: 2414: 2413: 2410: 2407: 2398: 2395: 2394: 2393: 2362: 2359: 2358: 2357: 2321: 2318: 2317: 2316: 2302: 2264: 2261: 2260: 2259: 2236: 2233: 2230: 2210: 2207: 2204: 2201: 2198: 2195: 2175: 2172: 2169: 2166: 2163: 2160: 2140: 2137: 2134: 2131: 2128: 2125: 2122: 2119: 2116: 2113: 2110: 2107: 2104: 2101: 2098: 2095: 2092: 2089: 2086: 2083: 2056: 2052: 2046: 2042: 2038: 2033: 2029: 2025: 2022: 2017: 2013: 2007: 2003: 1999: 1994: 1990: 1986: 1964: 1959: 1955: 1951: 1946: 1942: 1938: 1935: 1930: 1926: 1905: 1900: 1896: 1892: 1887: 1883: 1879: 1876: 1871: 1867: 1842: 1837: 1833: 1829: 1824: 1820: 1816: 1813: 1789: 1785: 1779: 1775: 1771: 1766: 1762: 1758: 1753: 1748: 1744: 1740: 1735: 1731: 1710: 1705: 1701: 1697: 1692: 1688: 1684: 1681: 1676: 1672: 1651: 1646: 1642: 1638: 1633: 1629: 1625: 1622: 1617: 1613: 1589:76.193.219.196 1579: 1578: 1577: 1576: 1553: 1550: 1547: 1544: 1541: 1538: 1535: 1532: 1497: 1494: 1491: 1488: 1485: 1482: 1479: 1476: 1456: 1453: 1450: 1447: 1444: 1441: 1438: 1435: 1411: 1391: 1371: 1368: 1365: 1362: 1359: 1356: 1353: 1350: 1330: 1327: 1324: 1321: 1318: 1315: 1312: 1309: 1289: 1286: 1283: 1280: 1277: 1274: 1271: 1268: 1248: 1228: 1208: 1205: 1202: 1199: 1196: 1193: 1173: 1153: 1150: 1147: 1144: 1141: 1138: 1135: 1132: 1129: 1126: 1123: 1103: 1091: 1090: 1089: 1088: 1087: 1086: 1072: 1071:satisfying..." 1068: 1052:is a function 1044: 1043: 1042: 1041: 1024: 1023: 978: 975: 917: 916: 913: 910: 906: 905: 902: 899: 895: 894: 891: 888: 884: 883: 880: 877: 873: 872: 869: 866: 862: 861: 858: 855: 851: 850: 847: 844: 840: 839: 836: 835:Math. Reviews 833: 820: 819: 813: 804: 795: 794: 786: 753: 750: 749: 748: 707: 704: 689: 683: 682: 668: 665: 662: 659: 656: 651: 647: 643: 640: 635: 632: 629: 626: 623: 618: 614: 603: 599: 595: 588: 583: 580: 577: 573: 569: 566: 563: 560: 557: 554: 551: 537: 536: 535: 534: 528: 512: 504: 495: 484: 481: 445: 444: 441: 437: 430: 425: 422: 421: 420: 398: 397: 396: 389: 386: 383: 375: 374: 373: 372: 371: 370: 329: 328: 309: 299: 298: 287: 277: 254: 240: 239: 238: 237: 236: 229: 228: 227: 226: 219: 218: 217: 216: 209: 208: 173: 170: 168: 164: 163: 160: 159: 156: 155: 144: 138: 137: 135: 118:the discussion 105: 104: 88: 76: 75: 67: 55: 54: 48: 37: 24: 14: 13: 10: 9: 6: 4: 3: 2: 3096: 3085: 3082: 3080: 3077: 3076: 3074: 3067: 3066: 3062: 3058: 3054: 3051: 3044: 3038: 3034: 3027: 3023: 3019: 3015: 3010: 3006: 3002: 2998: 2994: 2987: 2983: 2977: 2973: 2969: 2952: 2948: 2940: 2936: 2932: 2927: 2926: 2925: 2924: 2920: 2916: 2912: 2909: 2900: 2891: 2889: 2888: 2884: 2880: 2876: 2872: 2871:and Euclidean 2856: 2853: 2848: 2843: 2835: 2831: 2822: 2815: 2813: 2812: 2808: 2804: 2788: 2785: 2779: 2776: 2773: 2767: 2754: 2752: 2733: 2730: 2727: 2720: 2716: 2713: 2688: 2685: 2682: 2675: 2671: 2668: 2657: 2653: 2649: 2645: 2641: 2638: 2637: 2636: 2630: 2626: 2622: 2618: 2614: 2613: 2612: 2610: 2606: 2602: 2598: 2591: 2590:metric tensor 2587: 2579: 2575: 2571: 2567: 2563: 2562: 2561: 2558: 2554: 2550: 2546: 2542: 2535: 2527: 2525: 2524: 2520: 2516: 2508: 2505: 2502: 2499: 2496: 2493: 2490: 2487: 2484: 2481: 2478: 2475: 2472: 2469: 2466: 2463: 2462: 2461: 2455: 2452: 2449: 2446: 2443: 2440: 2439: 2438: 2435: 2432: 2425: 2423: 2422: 2419: 2411: 2408: 2404: 2403: 2402: 2396: 2392: 2389: 2387: 2386: 2380: 2379: 2378: 2377: 2373: 2369: 2360: 2356: 2353: 2351: 2350: 2344: 2343: 2342: 2341: 2337: 2333: 2328: 2325: 2319: 2315: 2311: 2307: 2303: 2301: 2297: 2293: 2289: 2288: 2287: 2286: 2282: 2278: 2274: 2270: 2262: 2258: 2254: 2250: 2234: 2231: 2228: 2205: 2202: 2199: 2193: 2170: 2167: 2164: 2158: 2135: 2132: 2129: 2123: 2120: 2114: 2111: 2108: 2102: 2099: 2093: 2090: 2087: 2081: 2074: 2054: 2044: 2040: 2036: 2031: 2027: 2020: 2015: 2005: 2001: 1997: 1992: 1988: 1957: 1953: 1949: 1944: 1940: 1933: 1928: 1924: 1898: 1894: 1890: 1885: 1881: 1874: 1869: 1865: 1856: 1835: 1831: 1827: 1822: 1818: 1811: 1787: 1777: 1773: 1769: 1764: 1760: 1751: 1746: 1742: 1738: 1733: 1729: 1703: 1699: 1695: 1690: 1686: 1679: 1674: 1670: 1644: 1640: 1636: 1631: 1627: 1620: 1615: 1611: 1602: 1601: 1600: 1598: 1594: 1590: 1586: 1575: 1571: 1567: 1551: 1548: 1542: 1539: 1536: 1530: 1522: 1521: 1519: 1515: 1511: 1495: 1492: 1486: 1483: 1480: 1474: 1454: 1451: 1445: 1442: 1439: 1433: 1425: 1409: 1389: 1369: 1366: 1360: 1357: 1354: 1348: 1328: 1325: 1319: 1316: 1313: 1307: 1287: 1284: 1278: 1275: 1272: 1266: 1246: 1226: 1203: 1200: 1197: 1191: 1184:floors). Let 1171: 1148: 1145: 1142: 1139: 1136: 1133: 1130: 1124: 1121: 1101: 1093: 1092: 1085: 1081: 1077: 1073: 1067: 1063: 1059: 1055: 1050: 1049: 1048: 1047: 1046: 1045: 1040: 1036: 1032: 1028: 1027: 1026: 1025: 1022: 1018: 1014: 1010: 1009: 1008: 1007: 1003: 999: 993: 992: 988: 984: 976: 974: 973: 969: 965: 961: 957: 953: 948: 947: 943: 939: 935: 930: 928: 924: 914: 911: 908: 907: 903: 900: 897: 896: 892: 889: 887:pseudometric 886: 885: 881: 878: 875: 874: 870: 867: 864: 863: 859: 856: 853: 852: 848: 845: 842: 841: 838:Zentralblatt 837: 834: 831: 830: 827: 824: 817: 814: 812: 808: 805: 803: 800: 799: 798: 791: 787: 784: 779: 775: 774: 773: 771: 767: 763: 759: 751: 747: 743: 739: 735: 734: 733: 732: 729: 725: 721: 717: 713: 710:The articles 705: 703: 701: 697: 692: 688: 663: 660: 657: 649: 645: 641: 638: 630: 627: 624: 616: 612: 601: 597: 593: 581: 578: 575: 571: 567: 561: 558: 555: 549: 542: 541: 540: 532: 524: 520: 515: 511: 507: 503: 499: 492: 491: 490: 489: 488: 482: 480: 478: 473: 471: 467: 463: 458: 456: 452: 448: 442: 438: 435: 431: 428: 427: 423: 419: 415: 411: 407: 403: 399: 394: 390: 387: 384: 381: 380: 377: 376: 369: 365: 361: 357: 356: 354: 350: 346: 345: 344: 343: 342: 340: 336: 332: 326: 322: 318: 314: 310: 307: 306: 305: 303: 296: 292: 288: 285: 281: 278: 275: 272: 271: 270: 268: 264: 260: 253: 249: 245: 241: 233: 232: 231: 230: 223: 222: 221: 220: 213: 212: 211: 210: 207: 203: 199: 195: 191: 190: 189: 188: 184: 180: 171: 169: 153: 149: 148:High-priority 143: 140: 139: 136: 119: 115: 111: 110: 102: 96: 91: 89: 86: 82: 81: 77: 73:High‑priority 71: 68: 65: 61: 56: 52: 46: 42: 38: 34: 29: 28: 19: 3049: 3042: 3036: 3032: 3025: 3021: 3017: 3013: 3008: 3004: 3000: 2996: 2992: 2985: 2981: 2975: 2971: 2950: 2946: 2943: 2907: 2895: 2874: 2870: 2827: 2758: 2660: 2655: 2651: 2647: 2643: 2639: 2634: 2595:— Preceding 2583: 2539:— Preceding 2531: 2512: 2459: 2436: 2433: 2429: 2415: 2400: 2384: 2364: 2348: 2329: 2326: 2323: 2266: 2072: 1854: 1580: 1423: 1065: 1061: 1057: 1053: 994: 980: 949: 931: 920: 909:quasimetric 825: 821: 811:pseudometric 802:pseudometric 796: 782: 762:metric space 755: 720:Metric space 709: 690: 686: 684: 538: 526: 522: 518: 513: 509: 505: 501: 493: 486: 474: 469: 465: 462:metric space 459: 406:Metric space 392: 348: 300: 294: 290: 274:metric space 267:metric space 259:metric space 256: 252:metric space 244:metric space 175: 167: 147: 107: 51:WikiProjects 40: 2879:Michal Grňo 2249:Marcosaedro 1583:—Preceding 1566:Marcosaedro 1510:Marcosaedro 1424:quasimetric 898:semimetric 876:hemimetric 816:quasimetric 487:I changed 313:mathematics 179:Mar10dejong 123:Mathematics 114:mathematics 70:Mathematics 3073:Categories 2418:Hans Adler 2292:Hans Adler 2263:Inline TeX 1076:Hans Adler 1013:Hans Adler 964:Hans Adler 938:Hans Adler 934:semimetric 927:hemimetric 865:premetric 854:prometric 843:prametric 807:semimetric 790:hemimetric 766:hemimetric 477:MathMartin 353:MathMartin 302:MathMartin 198:WillemienH 2650:) = 1 if 2431:metrics. 1721:(i.e, if 1239:to state 923:prametric 778:prametric 770:prametric 525:) / (1 + 3061:contribs 3053:uantling 3030:, where 2949:: X×X → 2919:contribs 2911:uantling 2597:unsigned 2553:contribs 2541:unsigned 2368:Gwideman 2332:Gwideman 1585:unsigned 912:138/273 901:236/112 893:386/254 890:821/311 738:PJTraill 716:Distance 498:( x, y ) 410:PJTraill 393:See also 360:PJTraill 321:topology 295:sameness 257:I split 41:redirect 2545:Ruin052 2385:Quondum 2349:Quondum 1855:maximum 1853:is the 1031:Jergosh 998:Jergosh 983:Jergosh 915:71/253 150:on the 2974:: S → 2834:length 2586:metric 2509:(1931) 2503:(1976) 2497:(1982) 2491:(1988) 2485:(1994) 2479:(1999) 2473:(1999) 2467:(2014) 2456:(2001) 2450:(2004) 2444:(2006) 904:98/84 871:12/15 868:21/14 758:metric 242:Split 47:scale. 2964:| ≤ 3 2958:with 2956:S ⊆ X 2654:< 2515:Kaba3 832:word 728:Míkka 696:Lethe 531:(x,y) 470:Notes 261:into 246:into 39:This 3057:talk 3003:) = 2935:talk 2915:talk 2883:talk 2857:8.49 2807:talk 2621:talk 2605:talk 2588:and 2570:talk 2549:talk 2519:talk 2372:talk 2336:talk 2310:talk 2306:DVdm 2296:talk 2281:talk 2277:Bdmy 2273:talk 2269:Bdmy 2253:talk 2186:and 1593:talk 1570:talk 1514:talk 1080:talk 1035:talk 1017:talk 1002:talk 987:talk 968:talk 942:talk 925:and 882:1/0 879:2/3 860:1/0 857:0/0 849:0/0 846:0/0 768:and 760:and 742:talk 700:Talk 500:= Σ 466:bugs 455:Talk 434:IMHO 414:talk 364:talk 339:Talk 317:IMHO 291:same 282:and 265:and 250:and 202:talk 192:See 183:talk 142:High 3020:), 2988:∈ S 1916:to 1662:to 1402:to 539:to 451:MFH 335:MFH 3075:: 3063:) 3059:| 3028:)) 2999:, 2984:, 2937:) 2921:) 2917:| 2885:) 2854:≈ 2809:) 2786:≥ 2731:− 2721:10 2686:− 2676:10 2646:, 2623:) 2607:) 2572:) 2555:) 2551:• 2521:) 2513:-- 2374:) 2338:) 2312:) 2298:) 2283:) 2255:) 2100:≥ 2037:− 2021:− 1998:− 1770:− 1752:≥ 1739:− 1595:) 1572:) 1549:≥ 1516:) 1452:≥ 1367:≤ 1285:≥ 1146:− 1137:… 1082:) 1064:→ 1060:× 1056:: 1037:) 1019:) 1004:) 989:) 970:) 944:) 744:) 718:, 714:, 698:| 661:− 628:− 587:∞ 572:∑ 453:: 449:— 416:) 366:) 351:? 337:: 333:— 204:) 185:) 3055:( 3050:Q 3043:d 3037:E 3033:d 3026:b 3024:( 3022:m 3018:a 3016:( 3014:m 3012:( 3009:E 3005:d 3001:b 2997:a 2995:( 2993:d 2986:b 2982:a 2976:R 2972:m 2962:S 2960:| 2951:R 2947:d 2933:( 2913:( 2908:Q 2904:— 2901:: 2897:@ 2881:( 2849:2 2844:6 2805:( 2789:0 2783:) 2780:y 2777:, 2774:x 2771:( 2768:d 2760:( 2737:) 2734:x 2728:y 2725:( 2717:+ 2714:1 2692:) 2689:x 2683:y 2680:( 2672:+ 2669:1 2656:y 2652:x 2648:y 2644:x 2642:( 2640:d 2619:( 2603:( 2568:( 2547:( 2517:( 2370:( 2334:( 2308:( 2294:( 2279:( 2271:( 2251:( 2247:. 2235:y 2232:= 2229:x 2209:) 2206:x 2203:, 2200:y 2197:( 2194:s 2174:) 2171:y 2168:, 2165:x 2162:( 2159:s 2139:) 2136:z 2133:, 2130:y 2127:( 2124:s 2121:+ 2118:) 2115:y 2112:, 2109:x 2106:( 2103:s 2097:) 2094:z 2091:, 2088:x 2085:( 2082:s 2055:2 2051:) 2045:0 2041:x 2032:1 2028:x 2024:( 2016:2 2012:) 2006:0 2002:t 1993:1 1989:t 1985:( 1963:) 1958:1 1954:x 1950:, 1945:1 1941:t 1937:( 1934:= 1929:1 1925:e 1904:) 1899:0 1895:x 1891:, 1886:0 1882:t 1878:( 1875:= 1870:0 1866:e 1841:) 1836:1 1832:e 1828:, 1823:0 1819:e 1815:( 1812:s 1788:2 1784:) 1778:0 1774:x 1765:1 1761:x 1757:( 1747:0 1743:t 1734:1 1730:t 1709:) 1704:1 1700:x 1696:, 1691:1 1687:t 1683:( 1680:= 1675:1 1671:e 1650:) 1645:0 1641:x 1637:, 1632:0 1628:t 1624:( 1621:= 1616:0 1612:e 1591:( 1568:( 1552:0 1546:) 1543:x 1540:, 1537:x 1534:( 1531:d 1512:( 1496:0 1493:= 1490:) 1487:x 1484:, 1481:x 1478:( 1475:d 1455:0 1449:) 1446:y 1443:, 1440:x 1437:( 1434:d 1410:x 1390:x 1370:0 1364:) 1361:x 1358:, 1355:x 1352:( 1349:d 1329:0 1326:= 1323:) 1320:x 1317:, 1314:x 1311:( 1308:d 1288:0 1282:) 1279:x 1276:, 1273:x 1270:( 1267:d 1247:y 1227:x 1207:) 1204:y 1201:, 1198:x 1195:( 1192:d 1172:n 1152:} 1149:1 1143:n 1140:, 1134:, 1131:0 1128:{ 1125:= 1122:X 1102:X 1078:( 1069:0 1066:R 1062:X 1058:X 1054:d 1033:( 1015:( 1000:( 985:( 966:( 940:( 818:. 740:( 691:i 687:a 667:) 664:y 658:x 655:( 650:n 646:p 642:+ 639:1 634:) 631:y 625:x 622:( 617:n 613:p 602:n 598:2 594:1 582:1 579:= 576:n 568:= 565:) 562:y 559:, 556:x 553:( 550:d 533:) 529:i 527:p 523:y 521:- 519:x 517:( 514:i 510:p 506:i 502:a 496:a 494:d 412:( 362:( 297:) 200:( 181:( 154:. 53:: 20:)

Index

Talk:Prametric space

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Mar10dejong
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08:15, 8 March 2016 (UTC)
#Axioms of a metric
WillemienH
talk
11:19, 8 March 2016 (UTC)
metric space
metric (mathematics)
metric space
metric space
metric (mathematics)
metric space
metric space
norm (mathematics)
normed vector space

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