Not signed in (Sign In)

Start a new discussion

Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

  • Sign in using OpenID

Site Tag Cloud

2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry bundles calculus categorical categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology colimits combinatorics complex-geometry computable-mathematics computer-science constructive constructive-mathematics cosmology deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry digraphs duality elliptic-cohomology enriched fibration foundations functional-analysis functor gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homotopy homotopy-theory homotopy-type-theory index-theory integration integration-theory k-theory lie lie-theory limit limits linear linear-algebra locale localization logic manifolds mathematics measure-theory modal modal-logic model model-category-theory monad monads monoidal monoidal-category-theory morphism motives motivic-cohomology nforum nlab noncommutative noncommutative-geometry number-theory of operads operator operator-algebra order-theory pages pasting philosophy physics pro-object probability probability-theory quantization quantum quantum-field quantum-field-theory quantum-mechanics quantum-physics quantum-theory question representation representation-theory riemannian-geometry scheme schemes set set-theory sheaf simplicial space spin-geometry stable-homotopy-theory stack string string-theory subobject superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory type type-theory universal variational-calculus

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to nForum
If you want to take part in these discussions either sign in now (if you have an account), apply for one now (if you don't).
    • CommentRowNumber1.
    • CommentAuthorJohn Baez
    • CommentTimeJul 16th 2010
    In the article categorification via groupoid schemes, I removed a distracting query box containing a discussion of how to get a double slash in TeX. The answer was that // works, but is ugly, while prettier things like \sslash may not work for people who don't have the font loaded.
    • CommentRowNumber2.
    • CommentAuthorTobyBartels
    • CommentTimeJul 20th 2010
    • (edited Jul 20th 2010)

    I put back a little bit of that box, with something approaching mathematical content. If you think that even that bit is useless, then feel free to take it out again. But if David is correct to say ‘One could write YXY \sslash X for this nerve’ (which is what I made him say now), then that ought to be in the article somewhere.

    • CommentRowNumber3.
    • CommentAuthorDavidRoberts
    • CommentTimeJul 20th 2010

    Edited a bit, incorporating the comment, and Ben’s reply, into the dot points. I deleted the box again.

    • CommentRowNumber4.
    • CommentAuthorJohn Baez
    • CommentTimeJul 20th 2010

    Okay, great. Unfortunately I see “One could write Y [little box containing the characters 2, 0, E, B arranged in a square] X for this nerve”, which makes me say to myself, “Yeah, one could write that…”

    • CommentRowNumber5.
    • CommentAuthorTobyBartels
    • CommentTimeJul 20th 2010

    Well, that’s why the Lab page also says that you could write Y//XY//X instead, if you can’t see the proper version.

    It’s all a question of which fonts you have installed. The character is there, and …

    … now that I look at it, it doesn’t look like it is the correct character after all! U+20EB is a combining character, and the correct character is U+2AFD. So this is a bug in iTeX.

    Can you see this, John and David? (It is the correct character, put in by hand, so with the wrong spacing.)


    • CommentRowNumber6.
    • CommentAuthorJohn Baez
    • CommentTimeJul 20th 2010

    I see a little box with a 2 A F D in it.

    • CommentRowNumber7.
    • CommentAuthorDavidRoberts
    • CommentTimeJul 20th 2010

    I see dead people.. :P I mean, I just see a gap. But then, I’m at work, on crusty old Firefox 3.0.1 I was mystified earlier, when I thought Toby was trying to say I could just write YX, but soon realised when I was editing.

    • CommentRowNumber8.
    • CommentAuthorTobyBartels
    • CommentTimeJul 20th 2010

    Depending on the computer I use, I see all kinds of things: blank spaces, boxes like John, and double slashes.

    • CommentRowNumber9.
    • CommentAuthorTobyBartels
    • CommentTimeJul 22nd 2010

    By the way, Jacques has fixed the iTeX bug that renders \slash as one character that y’all can’t see instead of another, correct character that y’all can’t see, although it hasn’t propagated to us yet.

Add your comments
  • Please log in or leave your comment as a "guest post". If commenting as a "guest", please include your name in the message as a courtesy. Note: only certain categories allow guest posts.
  • To produce a hyperlink to an nLab entry, simply put double square brackets around its name, e.g. [[category]]. To use (La)TeX mathematics in your post, make sure Markdown+Itex is selected below and put your mathematics between dollar signs as usual. Only a subset of the usual TeX math commands are accepted: see here for a list.

  • (Help)