From 97a90d54b464db02a3bbe2c54cb6aa5e0ab8c847 Mon Sep 17 00:00:00 2001
From: Ulrik Buchholtz <ulrikbuchholtz@gmail.com>
Date: Thu, 10 Aug 2023 15:19:11 +0100
Subject: [PATCH] first figure for the intro

---
 intro.tex | 40 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/intro.tex b/intro.tex
index 6150673..75eb6e7 100644
--- a/intro.tex
+++ b/intro.tex
@@ -49,12 +49,42 @@ \chapter{Introduction to the topic of this book}
 \item
   are these \emph{all} the symmetries?
 \item ``rotation'' indicates a \emph{motion}, through different squares, joining $\square$ with itself via a ``journey in the world of squares''.
-  \begin{quote}
-      (picture of a little stick figure tipping a square over on its side along a path containing snapshots of the loop: I can draw one if you accept my analog artistic skills).
-  \end{quote}
-
-  How is that reconcilable with a precise notion of symmetry?
 \end{enumerate}
+\begin{center}
+  \begin{tikzpicture}
+    \foreach \x/\s in {45/0,35/1,25/2,15/3,5/4,-5/5,-15/6,-25/7,-35/8,-45/9} {
+      \begin{scope}[xshift=\s cm]
+        \draw (\x:.3) -- (\x+90:.3) -- (\x+180:.3) -- (\x+270:.3) -- cycle;
+      \end{scope}
+    }
+    % stick figure pushing
+    \begin{scope}[thick,line cap=round]
+      \node[dot] at (-.3,.3) {};
+      \draw (-.4,.1) -- (-.212,.1);
+      \draw (-.5,-.1) -- (-.35,.2);
+      \draw (-.5,-.1) -- (-.35,-.1);
+      \draw (-.5,-.1) -- (-.6,-.2);
+      \draw (-.35,-.1) -- (-.38,-.3);
+      \draw (-.38,-.3) -- (-.33,-.3);
+      \draw (-.6,-.2) -- (-.78,-.28);
+      \draw (-.78,-.28) -- (-.73,-.3);
+    \end{scope}
+    % stick figure resting
+    \begin{scope}[thick,line cap=round,xshift=9cm]
+      \node[dot] at (.5,.35) {};
+      \draw (.5,.25) -- (.5,-.05);
+      \draw (.5,-.05) -- (.6,-.3);
+      \draw (.6,-.3) -- (.65,-.3);
+      \draw (.5,-.05) -- (.4,-.3);
+      \draw (.4,-.3) -- (.35,-.3);
+      \draw (.5,.25) -- (.65,.1);
+      \draw (.65,.1) -- (.5,-.02);
+      \draw (.5,.25) -- (.35,.15);
+      \draw (.35,.15) -- (.212,.212);
+    \end{scope}
+  \end{tikzpicture}
+\end{center}
+How is that reconcilable with a precise notion of symmetry?
 
 The answer to the first question clearly depends on the context.  If we allow reflections or even more exotic symmetries the answer is ``no''.  Each context has its own answer to what the symmetries of the square are.