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

Discussion Tag Cloud

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.
    • CommentAuthorUrs
    • CommentTimeOct 16th 2017
    • (edited Oct 16th 2017)

    I’ll be using the “Feynman slash notation” “A/A\!\!\!/” a little, for the Clifford algebra element associated with a given vector AA in the given inner product space.

    I forget if there is some native code to get this notation. Is there? Presently I am using the hack

    • CommentRowNumber2.
    • CommentAuthorRodMcGuire
    • CommentTimeOct 16th 2017
    • (edited Oct 16th 2017)

    \mathrlap{A}/ gives A/\mathrlap{A}/ while \mathrlap{/}A gives /A\mathrlap{/}A output.


    says there is a\slash accent but it seems to have no effect in the nForum and I don’t know what it is supposed to do. Nor does \boxed.

    • \overline {A} =A¯=\overline {A}

    • \underline {A} =A̲=\underline {A}

    • a\slash {A}b =ab=a\slash {A}b

    • a\boxed {A}b =ab=a\boxed {A}b

    • CommentRowNumber3.
    • CommentAuthorTobyBartels
    • CommentTimeDec 6th 2017
    • (edited Jan 3rd 2018)

    I see that the same hack has been used on the Wikipedia page since 2005.

    In plain TeX, \slash is a text-mode command that inserts a slash with a discretionary line break afterwards. In principle, LaTeX shouldn't allow it to be used in math mode, but they seem not to have bothered to forbid it.

    In iTeX, it seems to be an accent that works just like you’d expect on the Lab; I don't know why it doesn't work on the Forum, but we should probably use it on the Lab (at least until it breaks). I have an example sitting in the Sandbox (revision 1328).

    • CommentRowNumber4.
    • CommentAuthorTobyBartels
    • CommentTimeDec 6th 2017

    Actually, I went ahead and used it on Feynman slash notation. In the font that I currently see, it looks so-so on ‘AA’ but great on ‘\partial’ (for which it may have been optimized).

    • CommentRowNumber5.
    • CommentAuthorUrs
    • CommentTimeDec 6th 2017

    okay, thanks

    • CommentRowNumber6.
    • CommentAuthorMike Shulman
    • CommentTimeDec 6th 2017

    In real LaTeX, there is the cancel package.

    • CommentRowNumber7.
    • CommentAuthorRodMcGuire
    • CommentTimeDec 6th 2017

    tests for iTex accents

    see: nforum: feynman-slash-notation


    I currently have an example sitting in the Sandbox.

    If you link to the sandbox for your slash example you should give a version number, i.e. Sandbox/1328.

    I don’t know why it doesn’t work on the Forum

    (These examples appear in Sandbox/1332)

    I decided to test all the accents listed at

    \bar, \overline ( = \closure = \widebar), \underline, \vec, \widevec( = \overrightarrow), \overleftarrow, \dot, \ddot, \dddot, \ddddot, \tilde, \widetilde, \check, \widecheck, \hat, \widehat, \slash, \boxed

    • a\bar{A}b\bar{BBB}c\bar{\partial}d

    • aA¯bBBB¯c¯da\bar{A}b\bar{BBB}c\bar{\partial}d

    • a\overline{A}b\overline{BBB}c\overline{\partial}d

    • aA¯bBBB¯c¯da\overline{A}b\overline{BBB}c\overline{\partial}d

    • a\underline{A}b\underline{BBB}c\underline{\partial}d

    • aA̲bBBB̲c̲da\underline{A}b\underline{BBB}c\underline{\partial}d

    • a\vec{A}b\vec{BBB}c\vec{\partial}d

    • aAbBBBcda\vec{A}b\vec{BBB}c\vec{\partial}d

    • a\widevec{A}b\widevec{BBB}c\widevec{\partial}d

    • aAbBBBcda\widevec{A}b\widevec{BBB}c\widevec{\partial}d

    • a\overleftarrow{A}b\overleftarrow{BBB}c\overleftarrow{\partial}d

    • aoverleftarrowAboverleftarrowBBBcoverleftarrowda\overleftarrow{A}b\overleftarrow{BBB}c\overleftarrow{\partial}d

    • a\dot{A}b\dot{BBB}c\dot{\partial}d

    • aA˙bBBB˙c˙da\dot{A}b\dot{BBB}c\dot{\partial}d

    • a\ddot{A}b\ddot{BBB}c\ddot{\partial}d

    • aA¨bBBB¨c¨da\ddot{A}b\ddot{BBB}c\ddot{\partial}d

    • a\dddot{A}b\dddot{BBB}c\dddot{\partial}d

    • aAbBBBcda\dddot{A}b\dddot{BBB}c\dddot{\partial}d

    • a\ddddot{A}b\ddddot{BBB}c\ddddot{\partial}d

    • aAbBBBcda\ddddot{A}b\ddddot{BBB}c\ddddot{\partial}d

    • a\tilde{A}b\tilde{BBB}c\tilde{\partial}d

    • aA˜bBBB˜c˜da\tilde{A}b\tilde{BBB}c\tilde{\partial}d

    • a\widetilde{A}b\widetilde{BBB}c\widetilde{\partial}d

    • aA˜bBBB˜c˜da\widetilde{A}b\widetilde{BBB}c\widetilde{\partial}d

    • a\check{A}b\check{BBB}c\check{\partial}d

    • aAˇbBBBˇcˇda\check{A}b\check{BBB}c\check{\partial}d

    • a\widecheck{A}b\widecheck{BBB}c\widecheck{\partial}d

    • aAˇbBBBˇcˇda\widecheck{A}b\widecheck{BBB}c\widecheck{\partial}d

    • a\hat{A}b\hat{BBB}c\hat{\partial}d

    • aA^bBBB^c^da\hat{A}b\hat{BBB}c\hat{\partial}d

    • a\widehat{A}b\widehat{BBB}c\widehat{\partial}d

    • aA^bBBB^c^da\widehat{A}b\widehat{BBB}c\widehat{\partial}d

    • a\slash{A}b\slash{BBB}c\slash{\partial}d

    • abcda\slash{A}b\slash{BBB}c\slash{\partial}d

    • a\boxed{A}b\boxed{BBB}c\boxed{\partial}d

    • abcda\boxed{A}b\boxed{BBB}c\boxed{\partial}d

    In the nForum \overleftarrow is unknown while \slash and boxed silently eat their arguments. In nLab all of these work.

    NOTE however that some extra white space sometimes appears between letters.

    • CommentRowNumber8.
    • CommentAuthorRodMcGuire
    • CommentTimeDec 6th 2017
    • (edited Dec 6th 2017)

    I currently seem to be unable to save an edit the nLab with either of the 2 versions of Firefox I’m running even when I clear cookies. The error message says I need to have Javascript and cookies enabled which I do.

    I created the above Sandbox using Chrome which for some reason gives me a tiny 2 line text input window, but its big enough to paste into even if I can’t see what I pasted.

    I guess I have to track down whats wrong with my firefoxes, maybe by creating a new blank profile.

    • CommentRowNumber9.
    • CommentAuthorDavidRoberts
    • CommentTimeDec 7th 2017

    You can drag the edit box in Chrome to be bigger, just don’t drag it too far to the right, else when your mouse goes over the help panel, the edit box disappears from view, and on releasing the button you are stuck!

    • CommentRowNumber10.
    • CommentAuthorTobyBartels
    • CommentTimeJan 3rd 2018

    If you link to the sandbox for your slash example you should give a version number,

    Good point; fixed.

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)