5

Suppose I arrange the numbers 40, 30, 20, 10 in the corner positions of a 3*3 array. To be precise, the number 40 (resp. 30, 20, 10) is located at the top-left (resp., bottom-left, top-right, bottom-right) corner. I have 3 questions:

Q1. How to type a symbol at the left-middle position to indicate that 40 is larger than or equal to 30? I think the symbol looks like of shape "V" together with a vertical bar aside (at the left or right side of the shape "V").

Q2. How to type a symbol in the middle position of the array to mean that 40 is larger than or equal to 10? I imagine that it appears like a skew "V" with it mouth pointing to 40, and with a bar aside again.

Q3. How to type a single symbol at the middle position, meaning that "40 is larger than or equal to 10, and 30 is larger than or equal to 20"? I hope it looks like a brute-force combination of the symbol from Q2 and its analog.

I need these folk math symbols in a beamer presentation. Wish someone kindly give me a collection of feasible TeX codes to do them, so that I can learn how to make such symbols in TeX. Or, are there ready-made codes in any TeX packages? Thanks in advance!

Here is an MWE:

Thanks Henri. Here is an MWE:

\documentclass{amsart}
\begin{document}
\[
\begin{array}{ccc}
40 & > & 20\\
Q1 & Q2/Q3 & *\\
30 & > & 10
\end{array}
\]
\end{document}
4
  • Welcome to TeX.SX! Please help us to help you and add a minimal working example (MWE) that illustrates your problem. It will be much easier for us to reproduce your situation and find out what the issue is when we see compilable code, starting with \documentclass{...} and ending with \end{document}. – Henri Menke May 22 '14 at 7:13
  • \rotatebox will do the trick. – Seamus May 22 '14 at 7:34
  • The \rotatebox is perfectly adequate for your MWE however if you need arbitrary orientations for your symbol you may consider using TikZ (it does not load much extra stuff in beamer). Also, an Hasse diagram could be handy for Q3 – Bordaigorl May 22 '14 at 8:01
  • Yes I see. Hasse diagram is also a way to do it. Thanks Bordaigorl! – kwgl May 22 '14 at 15:00
5

To answer Q1 and Q2, with the help of \rotatebox from graphicx you can define two new commands:

\newcommand{\rotgeq}{\mathrel{\text{\rotatebox[origin=c]{-90}{$\geq$}}‌}}
\newcommand{\rotmedgeq}{\mathrel{\text{\rotatebox[origin=c]{-45}{$\geq$}}​}}

MWE

\documentclass{article}

\usepackage{amsmath}
\usepackage{graphicx}

\newcommand{\rotgeq}{\mathrel{\text{\rotatebox[origin=c]{-90}{$\geq$}}‌}}
\newcommand{\rotmedgeq}{\mathrel{\text{\rotatebox[origin=c]{-45}{$\geq$}}​}}

\begin{document}
\renewcommand{\arraystretch}{2} 
\[
\begin{array}{ccc}
  40      & \geq       & 20 \\
  \rotgeq & \rotmedgeq & \rotgeq \\
  30      & \geq       & 10
\end{array}
\]
\end{document} 

Output:

enter image description here

About your Q3, it could be feasible, but it would result in an unintelligible symbol, so I suggest you not to use a similar thing.

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  • Thanks for your solution and the suggestion, Karl! Actually you inspired me! Let me art it in Guru style. – kwgl May 22 '14 at 7:52
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I would not recommend to overlay two symbols. This will confuse the reader. You may help a bit by putting lines between your entries. Here is an example using XY-pic in order to give you an idea of what I mean:

% arara: pdflatex

\documentclass{amsart}
\usepackage{graphicx}
\newcommand{\rotgeq}[1]{\text{\rotatebox{#1}{$\geq$}}‌}
\usepackage[all]{xy}

\begin{document}
\xymatrix{%
40 \ar[dd] _{\geq} \ar[rr] ^-{>} \ar[ddrr]  ^-(.75){\rotgeq{-45}} |!{[dd];[rr]}\hole & & 20 \ar[dd] ^-{\ast} \\
& & \\
30 \ar[rr] _{>} \ar[uurr]  ^-(.75){\rotgeq{45}} & & 10
}
\end{document}

enter image description here

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  • This is a pretty-looking solution for the problem. Wishing a slide as concise as possible, I feel that removing the arrows might less distract the audiences. Thank you LaRiFaRi! – kwgl May 22 '14 at 15:09
  • Please just add @{-} to every arrow in the code above. E.g. 40 \ar@{-}[dd]. This and all other arrow styles can be read in the user guide mirrors.ctan.org/macros/generic/diagrams/xypic/doc/xyguide.pdf – LaRiFaRi May 23 '14 at 6:58
  • beautiful: to the uninitiated, you can also replace documentclass amsart with (say) \documentclass{standalone} and \usepackage{amsmath} – PatrickT Dec 1 '18 at 10:47

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