Package that contains square epsilon

Question

I am looking for an edgy/square epsilon like in the following, but haven't been able to find something. Can somebody point me to a package that provides it?

is that an epsilon? where does the image come from, if you have the pdf, you can see what font it is, — David Carlisle, Jun 23 '20 at 10:12
Its from this paper: https://arxiv.org/pdf/1605.03871.pdf. I don't know if it really is an epsilon. How do I find that out in a PDF? — Moritz Groß, Jun 23 '20 at 10:14
https://tex.stackexchange.com/questions/45919/how-do-i-find-out-what-fonts-are-used-in-a-document-picture — David Carlisle, Jun 23 '20 at 10:17

score 8 · Answer 1 · answered Jun 23 '20 at 10:29

You just download the source, which is a tarball, and extract it.

In the file arxiv_new.tex you find

\newcommand{\sqin}{%
  \mathrel{\vphantom{\sqsubset}\text{%
    \mathsurround=0pt
    \ooalign{$\sqsubset$\cr$-$\cr}%
  }}%
}

There is actually no need for the \vphantom, in this case, and with \mathpalette it's slightly more efficient.

\documentclass{article}
\usepackage{amsmath,amssymb}
\makeatletter
\newcommand{\sqin}{}% just in case
\DeclareRobustCommand{\sqin}{\mathrel{\mathpalette\sq@in\relax}}
\newcommand{\sq@in}[2]{%
  \ooalign{$\m@th#1\sqsubset$\cr$\m@th#1-$\cr}%
}
\makeatother
\begin{document}
$(w,I')\sqin N^{\Delta}(v,I)$
\end{document}

Thanks for your solution, it works for me. How to you find the source? I'm new to arxiv. Do I need to alter the URL I posted? I guess you got it from here: https://arxiv.org/format/1605.03871 — Moritz Groß, Jun 23 '20 at 14:05

benjamin · Answer 2 · 2020-06-23T10:42:13.040

I'm not sure whether my answer exactly solves the problem (sure egreg's does) because I didn't check how it looks in a MWE and if you'd obtain an exact reproduction of the original.

It seems to be the unicode character "U+22FF Z NOTATION BAG MEMBERSHIP", so you can copy/paste it (here you are: ⋿), find a font that has it, and compile with XeLaTeX or LuaLaTeX. I don't know if you need a math font that has it, since I never use mathmode and know almost nothing of its peculiarities with respect to fonts and unicode characters.

For the record: I used the "table de caractères" (character lookup table) function of my Linux Mint (should be there in many Linux flavours), I looked up the meaning in the linked article from arxiv (it says temporal membership), then I looked for these keywords, didn't find anything, so I reduced my search to just membership and bingo.

score 3 · Answer 3 · answered Jun 23 '20 at 16:01

The ⋿ symbol is \bagmember in stix, stix2 and unicode-math. The OpenType math fonts XITS Math and STIX Two Math both contain it.

\documentclass{article}
\usepackage{iftex}
\pagestyle{empty}
\ifTUTeX
  \usepackage{unicode-math}
  \setmainfont{STIX Two Text}[Scale = 1.0]
  \setmathfont{STIX Two Math}[Scale = MatchUppercase]
\else
  \usepackage[T1]{fontenc}
  \usepackage{amsmath}
  \usepackage{stix2}
\fi
\begin{document}
[ (w,I')\bagmember N^{\increment}(v,I) ]
\end{document}

In unicode-math, you can take this one symbol from STIX Two even if you are using a different math font.

\setmathfont[range={\bagmember}, Scale=MatchUppercase]{STIX Two Math}

With legacy font packages, the exact commands you would use for this vary from font to font. The fastest way to figure them out is to open stix2.sty or stix.sty, figure out the minimal set of commands needed to define that symbol, and copy them.

You could also try loading your font packages of choice over stix2 or stix, which should leave any commands defined only in those packages untouched. Legacy LaTeX limits you to 16 math alphabets, however, so you could easily run out that way.

Package that contains square epsilon

3 Answers3