[Tex/LaTex] LaTeX command for unknown symbol

symbols

I am trying to type the shown symbol in LaTeX and I am hoping to find a command producing this symbol. This is just a very crude sketch. The three lines are supposed to be equal length with 120 degrees between them. It is quite large here, but I would like it to be of "normal character size", comparable to a + or so. Is there any direct way of obtaining this without including it as a graphic or perhaps drawing it in TikZ?

Crude sketch of symbol

Best Answer

The following example constructs the symbol in the following way:

The top part with the round line end of the vertical bar is used as branch line.
The length of the branch is the same as in the plus symbol. But the length can be changed by redefining \UpDownYFactor to a value different than 1.
The intersection point is the same as in the plus symbol at the mathematical center axis.
The symbol adopts in size to the current math style.
The side bearings have the same width as in the plus symbol.
The names for the provided symbols are the same as in package MnSymbol: \upY and \downY.
The symbols act as binary operators. It can be changed by replacing \mathbin.

Example file:

\documentclass{article}
\usepackage{graphicx}
\usepackage{trimclip}

\makeatletter
\providecommand*{\upY}{%
  \mathbin{%
    \mathpalette\@updownY{0}%
  }%
}
\providecommand*{\downY}{%
  \mathbin{%
    \mathpalette\@updownY{1}%
  }%
}
\providecommand*{\UpDownYFactor}{1}
\newcommand*{\@updownY}[2]{%
  % #1: math style
  % #2: 0 = up, 1 = down
  \sbox0{$#1+\m@th$}%
  \dimen2=.5\dimexpr\wd0-\ht0-\dp0\relax
  % => \dimen2: side bearing
  \sbox2{$#1\vcenter{}$}%
  \dimen4=\dimexpr\ht0-\ht2\relax
  % => \dimen4: branch length
  \setbox0=\hbox to 0pt{%
    \hss
    \clipbox{%
      0pt %
      {\dimexpr\totalheight-\UpDownYFactor\dimen4\relax} %
      0pt %
      -\dimen2%
    }{$#1|$}%
    \hss
  }%
  \ht0=\dimexpr\ht0-\dimen2\relax
  \kern\dimen2 %
  \raise\ht2\hbox{%
    \ifnum#2=0 %
      {\rotatebox{120}{\copy0}}%
      \copy0 %
      {\rotatebox{-120}{\copy0}}%
    \else
      {\rotatebox{60}{\copy0}}%
      {\rotatebox{180}{\copy0}}%
      {\rotatebox{-60}{\copy0}}%
    \fi
  }%
  \kern\dimen2 %
}
\makeatother

\begin{document}
\[\begin{array}{c}
  a \upY b \downY c
  \\
  \scriptstyle
  a \upY b \downY c
  \\
  \scriptscriptstyle
  a \upY b \downY c
  \\
  \rlap{$\upY$}{\downY}
\end{array}\]
\end{document}

For analyzing the center:

\usepackage{pdfrender}
...
\[
  \rlap{%  
    \sbox0{$\vcenter{}$}%
    \sbox2{${\upY}{\downY}{\upY}$}%
    \raise\ht0\hbox{\vrule height.01pt depth.01pt width\wd2}%
  }%
  \pdfrender{TextRenderingMode=Stroke, LineWidth=.01pt}
  {\upY}\rlap{$\upY$}{\downY}{\downY}
\]

Unicode/OpenType/TrueType fonts

These fonts require LuaLaTeX or XeLaTeX.

The glyph is contained in Deja Vu Sans:

\documentclass{standalone}
\usepackage{fontspec}
\setmainfont{DejaVuSans.ttf}
\pagestyle{empty}
\begin{document}%
^^^^267e%
\end{document}

Font XITS/xits-regular.otf:

Font STIXGeneral-Regular/STIXGeneral.otf:

Solution with `TikZ`

Without a font that contains the symbol, it can be constructed with tikz, for example:

\documentclass{standalone}
\usepackage{tikz}
\pagestyle{empty}
\begin{document}
\tikz\node[circle,draw,inner sep=.1ex] {$\infty$};
\end{document}

Edit: If you are using LuaLaTeX or XeLaTeX, then the symbol can be used directly as unicode character:

\usepackage{fontspec}
...
\begingroup
  \fontspec{STIXGeneral.otf}
  ♾% or ^^^^267e%
\endgroup

The TikZ solution also works with other TeX compilers.

I have edited the examples to use document class standalone. Thus the examples generate a PDF page with the symbol. The margins are cropped entirely (solution via TikZ) or to the bounding box of the characters (solutions with Unicode fonts). The PDF file can directly be included in pdflatex (or xelatex). Or it can be converted to PostScript to support latex/dvips, e.g. via pdftops of xpdf:

pdftops -eps PermanentPaperSign.pdf PermanentPaperSign.eps

Alternative converters: ghoscript, …

This avoids including a bitmap file (.png).

[Tex/LaTex] LaTeX command for symbol needed. looks like crossed equal

Well here is one that looks kinda like cheating, it uses amsmath only, though adding calc will make the definition much simpler:

\documentclass{article}
\usepackage{amsmath}

\newlength{\crossl}
\settowidth{\crossl}{$\times$}
\newlength{\ceql}
\settowidth{\ceql}{$\times=$}
\addtolength{\ceql}{-\crossl}
\newcommand{\crosseq}{\mathrel{\makebox[\crossl][l]{$\times\hspace{-\ceql}=$}}}

\begin{document}
$f(x)\crosseq g(x)\crosseq h(x)$
\end{document}

Result:

enter image description here

One can also play around with the position and the symbols used:

\newcommand{\crosseq}{\mathrel{\makebox[7.7778pt][l]{$\neq$\hspace{-6.7778pt}\raisebox{-2.5pt}{$\backslash$}}}}

enter image description here

EDIT: Since this answer is chose I will add some more solution, this time using egreg's suggestion as poking around with boxes will likely create unexpected spacing issue:

\newcommand{\crosseq}{\mathrel{\ooalign{\hidewidth$/$\hidewidth\cr\ooalign{\hidewidth$\backslash$\hidewidth\cr$=$\cr}\cr}}}

\newcommand{\crosseq}{\mathrel{\ooalign{\hidewidth$/$\hidewidth\cr\ooalign{\hidewidth\raisebox{-2pt}{$\backslash$}\hidewidth\cr$=$\cr}\cr}}}

Result:

enter image description here

EDIT2: Add [l] option to \makebox in order to adjust alignment.

Best Answer

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Unicode/OpenType/TrueType fonts

Solution with TikZ

[Tex/LaTex] LaTeX command for symbol needed. looks like crossed equal

Related Question

Solution with `TikZ`