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    • I have added to Kan extension in the section on the pointwise coend formula some elementary illustrative discussion of the case of left Kan extension of presheaves, that some readers might benefit from at this point, see this example.

    • Someone (at Waldhausen category changed axiom C3) as it was incorrect. The new version still looked wrong, and I have changed it further. (Could someone check that I have got it right now!)

    • I don’t like the name of the page complete topological space; it seems to suggest that a property of “completeness” can be defined for topological spaces, when in fact one needs additional structure on a topological space (like a metric, a uniformity, or at least a Cauchy structure) in order to say what “complete” means. Since the notion of Cauchy space seems to be the maximum generality in which the notion applies, how about renaming the page to “complete Cauchy space”?

    • I have been adding some material to Cocomm Coalg. I’m not sure where I first read that this category is extensive, and hope that a relatively painless proof of that can be produced.

    • It's really the reflection of topological spaces within a larger category, but usually people think of it as underlying: underlying topological space.

    • Apparently, the page mathematicscontents, despite being included in a number of other pages, has not existed since shortly after it was spammed slightly more than a year ago. So before blanking a spam page, make sure that it has no history! I have restored it now (although it took a little bit to figure out what it had been called, since it doesn't follow the standard naming format for included contents).

    • I added a hatnote to syntactic category remarking on an alternative usage of the phrase.

    • I have expanded the text in the entry on Eric Sharpe a little, and added a list of publications. The recent one

      reviews and expands on aspects of higher groups/stacks/gerbes in QFT and string theory in a style that ought to appeal to people with physics background.

    • I came across a non-standard definition of “regular monomorphism” in Cassidy/Hébert/Kelly’s “Reflective subcategories, localizations and factorizations systems.” and added a note to the nlab page. They define a regular mono to be a joint equalizer of an arbitrary family of parallel pairs. This is more general than the usual definition, and forces the class of regular monos to be closed under arbitrary intersections.

      I think that in a well powered category with small products the definition should coincide with the usual one, and in coregular categories both should coincide with “strong mono”.

      Any comments? Does this definition of regular mono appear anywhere else? Or is there maybe an alternative term for it?

    • Wrote superextensive site, with a purported proof that sheafification for the single covers does preserve extensive-sheaves in that case.

    • have started a category:reference entry on

      and have added pointers to it from relevant entries

    • I added redirets Atiyah sequence, Atiyah class, Atiyah algebroid to Atiyah Lie algebroid. Maybe we want to have Lie algebroid aspect (concentrating on bracket) and the cohomological/derived category aspect (cohomology class of the exact sequence of modules) separate in fuiture, but now the material is still too small. I added a number of interesting references and a sentence on the class.

    • added a few items to the References section at GUT, both on theoretical background as well as on fits to the latest experimental data. According to these, the SO(10)SO(10)-model seems to be well alive, susy or not.

    • I have created a new entry

      meant as a disambiguation page for the various different kinds of definitions that exists. Presently it points to the entries

      that already provide dedicated discussion of special defintiions. In addtion it lists references that have further proposals for defintion which don’t at the moment however have dedicated nnLab pages associated with them.

    • I just noticed we miss an entry n-vector space. I’d like to start it, but I only have a very vague idea, recursively implementing the notion of Baez-Crans 2-vector space. something like: an nn-vector space is an (n1)(n-1)-category of modules over a (n1)(n-1)-Vect enriched symmetric monoidal (n1)(n-1)-category.

      how far is this from the correct notion?

    • I was going to add a stub page on Roland Schwänzl, to avoid grey links, and linking to the Wikipedia page, but looking at that I am very confused (and my German is too rusty!) That page seems to be about two people or did Roland Schwänzl actually do things on UNIX etc as well as working with Vogt? My search did not even give me the genealogy page for him, (although I now have found it).. Can anyone help?

    • I fixed a link that was not working. (The brackets were interfering with the link address.) see here

    • I created Hoàng Xuân Sính as a result of recent G+ discussion, and David Eppstein creating an English Wikipedia page for her. There is now a link to that page at 2-group and a(n updated) link to her thesis.

    • for those who check the logs and are wondering: I went through a fairly long list of category:people-entries on people based in and around London, updating affiliation links, references and related nnLab entries.

    • I tried to start an entry theta function, but it’s hard to tell for me if anything of it has been saved. The nnLab is too busy doing something else than serving pages.

    • I am starting a table of contents theta functions - contents and am including it as a “floating table of contents” into relevant entries

    • made explicit in the Idea section of functional equation the statement that the functional equation of a zeta function is the incarnation under Mellin transform of the automorphy of the automorphic form that it comes from

    • I added a few comments to Hilbert basis theorem about related work by Gordon and Noether (chronologically, on either side of Hilbert’s work).

    • I had begun adding to prime ideal theorem (en route adding to compactness theorem), but have decided to stop midstream because it looks as though much more general results are known, which I’d need to read up on it before writing further.

      One thing I’ll mention now is that the surmise (due to Toby?) that UF is equivalent to the prime ideal theorem for rigs seems to be known and subsumed under these general results. Banaschewski’s name comes up as one having a key lattice-theoretic insight into this topic: “Every nontrivial distributive complete lattice with a compact top element contains a prime element.”

    • The entry finite field was looking a little sad, so I added to it.

    • Do we have a page about natural transformations between (,1)(\infty,1)-categories? I wanted to add a link to this paper (working today on catching up with the arXiv…) but I couldn’t find where to put it.

    • We have a bit of a mess of closely related entries related to étale homotopy groups which existed more or less in parallel without seeming to know much of each other. I have tried to do some minimum of cross-linking and cleaning up, but this needs more attention.

      There is more even, there is Grothendieck’s Galois theory and what not. (Maybe we need to wait until somebody gives a course on this and uses the occasion to clean it all up and harmonize it.)

    • I’ve slowly been trying to improve the article topological map since this thread. I just added a small note on embedded graphs versus abstract graphs, motivated by Bruce Bartlett’s interesting recent post at the n-café.

    • I created a stub for falling factorial, mainly to record the simple fact I learned yesterday that it counts the number of injections between two finite sets.