Talk:Join and meet

message: I changed this from a redirect to Lattice (order) to an article.  Cf. Talk:Join (mathematics) for further discussion. JoergenB 20:05, 21 September 2006 (UTC)
thread_title:  Changed redirect 

message: Could someone please explain how these common English words "join" and "meet" came to stand for "least upper bound" and "greatest lower bound"? On the face of it, they don't seem the slightest bit intuitive as names for these concepts. I have some hope that an explanation for this naming might aid in remembering what they refer to.  Gwideman (talk) 00:12, 23 August 2012 (UTC)
replies: text: Probably from the Boolean algebra: if the elements of your poset are sets, the join is the union (what you get when you join them together) and the meet is the intersection (where they meet).  The notations (which are otherwise regrettable) reinforce this.  I do not know off-hand of a reliable source for this. --JBL (talk) 00:53, 23 August 2012 (UTC)
replies: text:  Ah, that sounds plausible for some particular cases, as you point out. Thanks. Gwideman (talk) 09:23, 24 August 2012 (UTC)
thread_title:  Explain these names? 

message: This article talks about sets when it should be talking about subsets. The concepts of suprema and infima only make sense when you are talking about subsets, otherwise you may as well be talking about maximal and minimal elements. (Of course, a subset of a set may be the set itself but that is a special case.)  — Preceding unsigned comment added by Eptified (talk • contribs)  02:24, 22 June 2013 (UTC)
replies: text: Nonsense.  As usual, when you attempt to talk about mathematical concepts.  — Arthur Rubin  (talk) 07:19, 24 June 2013 (UTC)
replies: text: Please comment on the content not the contributor.  Spectral sequence (talk) 18:48, 5 July 2013 (UTC)
thread_title:  Subsets 

message: What is the difference to Infimum and supremum? Why are there two articles? --Tobias (Talk) 12:07, 18 May 2018 (UTC)
replies: text: Good question! --JBL (talk) 12:10, 18 May 2018 (UTC)
replies: text:   Join and meet are operations of an algebraic structure, infimum and supremum are elements of an ordered set. One can talk about the latter without having the former, and one can talk about the former without caring about the induced order. Consider it the Hesperus and Phosphorus of math. ;) Paradoctor (talk) 23:24, 21 February 2019 (UTC)
thread_title:  Difference to [[Infimum and supremum]]? 

message: Why is antisymmetry shown in the table as not being a property of the strict orders? Though it is trivially true, wouldn't it be at a minimum misleading to place an X in that column?
The note at the bottom of the table states that the check mark indicates the property is "required" by the definition. If I understand correctly, that is saying an X means the property does not hold in general, though it may in certain instances. But that would not be the case here, so it should be checked.
If instead, "required" by the definition meant something along the lines of not being merely a consequence of the definition, then couldn't asymmetry be treated the same way, as it is a consequence of other properties required by the definition? 2601:190:400:40D0:40CC:59A7:150D:A429 (talk) 10:40, 14 January 2022 (UTC)
thread_title:  Strict orders not antisymmetric?