Improve automata diagrams

README.md

@@ -239,9 +239,11 @@ Execution starts at the start state of the base automaton.  A stack of states is
 
 A sequence of input symbols is recognized if this process leaves us in an accepting state of the base automaton.
 
-Here's a quick drawing of what the two automata look like for this [grammar of nested arrays](https://ianh.github.io/owl/try/#nested): `a = [ '[' (a (',' a)*)? ']' ]`.
+Here's a visual representation of what the two automata look like for this [grammar of nested arrays](https://ianh.github.io/owl/try/#nested):
 
-| <img src="doc/base-automaton.png" width=162 height=57> | <img src="doc/bracket-automaton.png" width=225 height=187> |
+`a = [ '[' (a (',' a)*)? ']' ]`
+
+| <img src="doc/base-automaton.png"> | <img src="doc/bracket-automaton.png"> |
 | :---: | :---: |
 | *base automaton* | *bracket automaton* |
 

doc/automata.tex

@@ -0,0 +1,45 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% PREAMBLE
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\documentclass[11pt]{article}
+
+% packages needed for state diagrams
+\usepackage{pgf}
+\usepackage{tikz}
+\usetikzlibrary{arrows,automata}
+
+% page margins
+\usepackage[margin=2.5cm]{geometry}
+\setlength{\parindent}{0pt}
+
+\begin{document}
+
+\begin{center}
+    \begin{tikzpicture}[->,>=stealth',shorten >=1pt,auto,node distance=2.8cm,semithick]
+        \tikzstyle{every state}=[fill=white,draw=black,text=black]
+        \node[initial,state] (s0) {};
+        \node[state,accepting] (s1) [right of=s0] {};
+    \path
+        (s0) edge node {$[\ ]_{,}$} (s1);
+    \end{tikzpicture}
+\end{center}
+
+\bigskip
+
+\begin{center}
+    \begin{tikzpicture}[->,>=stealth',shorten >=1pt,auto,node distance=2.8cm,semithick]
+        \tikzstyle{every state}=[fill=white,draw=black,text=black]
+        \node[initial,state] (s0) {};
+        \node[state] (s1) [right of=s0] {};
+        \node[state] (s2) [below of=s1] {};
+        \node[state] (s3) [below of=s2] {};
+        \node[state,accepting,rectangle] (s4) [right of=s1] {$[\ ]_{,}$};
+    \path
+        (s0) edge node {[} (s1)
+        (s1) edge node {]} (s4) edge node {$[\ ]_{,}$} (s2)
+        (s2) edge [bend right] node [swap] {'} (s3) edge [bend right] node {]} (s4)
+        (s3) edge [bend right] node [swap] {$[\ ]_{,}$} (s2);
+    \end{tikzpicture}
+\end{center}
+\end{document}