Command for transverse, and not \pitchfork, as used in Guillemin and Pollack

Question

In Guillemin and Pollack's Differential Topology book, they use the notion of transverse, but not the \pitchfork to denote it. It is very similar, but has a 'T' in it instead of just a ' | ' in the symbol.

The following picture (taken from the book preview in Google Books, page 68) shows the symbol

enter image description here

I and my peers have searched for a convenient way to produce this symbol, but the quick and easy ways produce unsatisfying result, such as \overline and \bar. Before we go and draw one and make a command, I thought I would see if anyone has knowledge of this being available in some package or a better way to get what we want. Thanks.

Welcome to TeX.SX! I have added an image taken from the preview on Google Books — egreg, Sep 24 '13 at 13:28
this symbol is unicode 2ADA, "pitchfork with tee top". it should be found in the xits or stix fonts; i believe the name assigned is \topfork. — barbara beeton, Sep 24 '13 at 13:55

score 14 · Accepted Answer · answered Sep 24 '13 at 13:48

Here's a way to construct the symbol:

\documentclass{article}
\usepackage{amsmath,amssymb}

\newcommand{\transv}{\mathrel{\text{\tpitchfork}}}
\makeatletter
\newcommand{\tpitchfork}{%
  \vbox{
    \baselineskip\z@skip
    \lineskip-.52ex
    \lineskiplimit\maxdimen
    \m@th
    \ialign{##\crcr\hidewidth\smash{$-$}\hidewidth\crcr$\pitchfork$\crcr}
  }%
}
\makeatother

\begin{document}
$f_{s} \transv Z$

$X_{f_{s} \transv Z}$
\end{document}

If you don't plan to use the symbol in sub/superscripts, you may remove the \text around \tpitchfork.

enter image description here

If you'd like to lower the symbol, add something like \raise-0.1ex just before \vbox in the definition of \tpitchfork and adjust the 0.1 to suit.

\newcommand{\tpitchfork}{%
  \raise-0.1ex\vbox{
    \baselineskip\z@skip
    \lineskip-.52ex
    \lineskiplimit\maxdimen
    \m@th
    \ialign{##\crcr\hidewidth\smash{$-$}\hidewidth\crcr$\pitchfork$\crcr}
  }%
}

shouldn't this be centered vertically on the math axis? also, the name \topfork has been assigned in the stix fonts latex support (not yet fully released), so it would be reasonable to keep the same name in order to avoid possible later confusion. — barbara beeton, Sep 24 '13 at 13:58

score 4 · Answer 2 · answered Dec 02 '19 at 22:19

4

I was also looking for this and found it in the UTF-8 character library listed as "Pitchfork With Tee Top"

UTF-8 character: ⫚ (Hex code: U+2ADA)

Interestingly though there is also a character next to it called "Transversal Intersection".

UTF-8 character: ⫛ (Hex code: U+2ADB)

My Math teacher uses the former one (as in your question), so it may be a legitimate use of that symbol. Maybe both are acceptable alternatives? I'm not an expert.

answered Dec 02 '19 at 22:19

Bill

213

1

You might add that this symbol is in the packages stix, stix2 and unicode-math. – Davislor Nov 05 '20 at 18:43

Davislor · Answer 3 · 2020-11-05T19:19:32.787

Barbara Beeton and Bill say what this symbol is in Unicode, but not how to actually get it.

In LuaLaTeX or XeLaTeX:

\documentclass{article}
\tracinglostchars=2
\usepackage{unicode-math}
% Select any math font that has \topfork, and a matching text font.
\setmathfont{NewCMMath-Book.otf}
\begin{document}
[ f_S \topfork Z ]
\end{document}

Fonts that contain this symbol include XITS Math, STIX Two Math, and New Computer Modern Math. The \tracinglostchars=2 command will print a warning if you are using one that does not.

You could also combine this one symbol with a different math font that doesn’t contain it. An example that uses Latin Modern Math as the main math font, but takes this one symbol from New Computer Modern and scales it to the same height:

\setmathfont{Latin Modern Math}
\setmathfont{NewCMMath-Regular.otf}[range=\topfork, Scale=MatchUppercase]

In legacy TeX, several packages contain \topfork, including stix and stix2.

Steven B. Segletes · Answer 4 · 2013-09-24T15:25:01.173

This package constructs the symbol in \textstyle using the \stackinset macro from stackengine. Then, it uses the \scalerel macro of the package of the same name to scale that construct to the vertical size of a \pitchfork in the current math style. It imports that current math style into the \raisebox by way of the \ThisStyle{...\SavedStyle...} syntax.

\documentclass{article}
\usepackage{amssymb}
\usepackage{stackengine}[2013-09-11]
\usepackage{scalerel}
\stackMath
\def\ptt{\mathrel{\ThisStyle{\raisebox{-.2ex}{$\SavedStyle\scalerel*%
    {\stackinset{c}{}{t}{.5ex}{\smash{-}}{\pitchfork}}{\pitchfork}$}}}}
\begin{document}
\( A  \ptt C_{(A \ptt C)} \)
\end{document}

enter image description here

score 0 · Answer 5 · edited Nov 05 '20 at 18:41

Got the idea here: https://tex.stackexchange.com/a/21647

Try this:

\makeatletter
\newcommand{\superimpose}[2]{%
  {\ooalign{$#1\@firstoftwo#2$\cr\hfil$#1\@secondoftwo#2$\hfil\cr}}}
\makeatother
\newcommand{\transversal}{\mkern-1mu\mathrel{\mathpalette\superimpose{{\top}{\scrunch{\cap}}}}\mkern-1mu}
\newcommand{\scrunch}[1]{\resizebox{\width}{.9\height}{$#1$}}

In document:

\[
f_{s}\transversal Z
\]

Command for transverse, and not \pitchfork, as used in Guillemin and Pollack

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