[Tex/LaTex] How to create a rectangle symbol

symbols

I need to represent symmetries of a a rectangle as a set, and in my text book they do so by using the following notation

S(SYMBOL-THAT-LOOKS-LIKE-A-RECTANGLE)

I searched everywhere, tried http://detexify.kirelabs.org/classify.html and no luck. So, I came to terms with there not being any rectangle, and the closest I have been able to get is

$s\sqsubset\sqsupset$

Is there any way I can reduce the spacing between them so they make a better rectangle?

Best Answer

This is U+25AD (▭) and available as \hrectangle in unicode-math (if using xelatex or lualatex) or stix if using pdflatex (and will be available in other font packages that cover the Unicode math blocks)

enter image description here

\documentclass{article}

\usepackage{stix}

\begin{document}

$a \hrectangle b $

\end{document}

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[Tex/LaTex] Relation symbol used by Conway in On Numbers and Games

Edit: Following TH's advice, this would be a better command to use:

\newcommand{\trel}{\mathrel{\mathsurround=0pt \mbox{\raisebox{1.2pt}{\tiny \textbf{\textbar }}$\rhd$}}}

(I decided to explicitly say \mathsurround=0pt rather than just calling \m@th because that way, if Mike wants to paste this into the top of his document, he won't have to call \makeatletter)

Original: I don't know what built-in symbols would correspond to the one you're describing, but if you're just trying to get something done you could use this:

\newcommand{\trel}{\mbox{\raisebox{1.2pt}{\tiny \bf \textbar }$\rhd$}}

(and then use \trel every time you want to use this relation).

It's a huge hack, but, like I said, it might be enough to get you by.

[Tex/LaTex] different plus/minus within braket environment

I am not too sure what font to use for the internal + and -, so I just used \hbox{\texttt{+}}. In TeX, each character has a \mathcode, describing its behavious in maths. All of them lie between "0000 and "7FFF (in hexadecimal), except the special mathcode "8000, which makes the character act like an active character. Within the group which \bra, \ket and \braket define, I get + and - to be active and expand to \braket@inner@minus and \braket@inner@plus.

\documentclass{article}
\usepackage{braket}

\makeatletter
\newcommand{\braket@inner@minus}{\hbox{\texttt{-}}}
\newcommand{\braket@inner@plus}{\hbox{\texttt{+}}}
\begingroup
\catcode`\-=13\relax %active
\catcode`\+=13\relax %active
\@firstofone{\endgroup %end the local changes to catcodes.
  \newcommand\braket@inner@defs{%
    \edef\restore@mathcode{%
      \mathcode`\noexpand +=\the\mathcode`+%
      \mathcode`\noexpand -=\the\mathcode`-%
    }%
    \mathcode`\+="8000\relax
    \mathcode`\-="8000\relax
    \def+{\begingroup\restore@mathcode\braket@inner@plus\endgroup}%
    \def-{\begingroup\restore@mathcode\braket@inner@minus\endgroup}%
  }%
}
% old definition:
% \newcommand{\bra}[1]{\mathinner {\langle {#1}|}}
% new definition:
\renewcommand{\bra}[1]{\mathinner {\langle \braket@inner@defs {#1}|}}
\renewcommand{\ket}[1]{\mathinner {|\braket@inner@defs{#1}\rangle }}
\renewcommand{\braket}[1]{\mathinner {\langle \braket@inner@defs {#1}\rangle }}
\makeatother

\begin{document}
\[
\bra{++--}A^\dag A\ket{-+-+} = \braket{++--|A^\dag A|-+-+} = \cdots
\]
However, 
\[
\bra{++}(A+B)\ket{--} \neq \braket{++|(A+B)|--}
\]
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Relation symbol used by Conway in On Numbers and Games

[Tex/LaTex] different plus/minus within braket environment

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