slides/src/slides.tex
author Eugen Sawin <sawine@me73.com>
Fri, 22 Jul 2011 23:11:53 +0200
changeset 73 271b2a5270c1
parent 72 722ec2a3cabe
child 74 9938ea8ed067
permissions -rw-r--r--
Almost finished.
sawine@55
     1
\documentclass[9pt]{beamer}
sawine@55
     2
\usetheme{Boadilla}
sawine@58
     3
\usecolortheme{dove}
sawine@58
     4
\usecolortheme{orchid}
sawine@58
     5
\usecolortheme{dolphin}
sawine@58
     6
%\usecolortheme{seagull}
sawine@58
     7
sawine@60
     8
\usepackage{amsmath, amsthm, amssymb, amsfonts, verbatim}
sawine@62
     9
\usepackage{pifont}
sawine@72
    10
\usepackage{multicol}
sawine@61
    11
\usepackage{xcolor}
sawine@58
    12
\usepackage{ulem}
sawine@66
    13
\usepackage{graphics}
sawine@58
    14
\usepackage{tikz}
sawine@58
    15
\usetikzlibrary{automata}
sawine@58
    16
\usepackage{subfigure}
sawine@55
    17
sawine@61
    18
\renewcommand{\emph}{\textit}
sawine@66
    19
\renewcommand{\em}{\it}
sawine@62
    20
sawine@62
    21
\newcommand{\cross}{\ding{55}}
sawine@55
    22
\newcommand{\M}{\mathcal{M}}
sawine@55
    23
\newcommand{\N}{\mathbb{N}_0}
sawine@55
    24
\newcommand{\F}{\mathcal{F}}
sawine@57
    25
\newcommand{\Fs}{\mathbb{F}}
sawine@55
    26
\newcommand{\Prop}{\mathcal{P}}
sawine@55
    27
\newcommand{\A}{\mathcal{A}}
sawine@55
    28
\newcommand{\X}{\mathcal{X}}
sawine@55
    29
\newcommand{\U}{\mathcal{U}}
sawine@55
    30
\newcommand{\V}{\mathcal{V}}
sawine@55
    31
\newcommand{\dnf}{\mathsf{dnf}}
sawine@55
    32
\newcommand{\consq}{\mathsf{consq}}
sawine@55
    33
sawine@55
    34
\theoremstyle{definition} %plain, definition, remark, proof, corollary
sawine@55
    35
\newtheorem*{def:finite words}{Finite words}
sawine@55
    36
\newtheorem*{def:infinite words}{Infinite words}
sawine@55
    37
\newtheorem*{def:regular languages}{Regular languages}
sawine@55
    38
\newtheorem*{def:regular languages closure}{Regular closure}
sawine@55
    39
\newtheorem*{def:omega regular languages}{$\omega$-regular languages}
sawine@55
    40
\newtheorem*{def:omega regular languages closure}{$\omega$-regular closure}
sawine@55
    41
\newtheorem*{def:buechi automata}{Automaton}
sawine@56
    42
\newtheorem*{def:automata runs}{Run}
sawine@56
    43
\newtheorem*{def:inf}{Infinite occurrences}
sawine@55
    44
\newtheorem*{def:automata acceptance}{Acceptance}
sawine@56
    45
\newtheorem*{def:automata language}{Recognised language}
sawine@57
    46
\newtheorem*{def:general automata}{Generalised automaton}
sawine@55
    47
\newtheorem*{def:general acceptance}{Acceptance}
sawine@61
    48
\newtheorem*{def:syntax}{Syntax}
sawine@72
    49
\newtheorem*{def:program}{Program}
sawine@72
    50
\newtheorem*{def:program automaton}{System automaton}
sawine@61
    51
sawine@55
    52
\newtheorem*{def:vocabulary}{Vocabulary}
sawine@62
    53
\newtheorem*{def:frames}{Frame}
sawine@62
    54
\newtheorem*{def:models}{Model}
sawine@55
    55
\newtheorem*{def:satisfiability}{Satisfiability}
sawine@55
    56
\newtheorem*{def:fs closure}{Closure}
sawine@55
    57
\newtheorem*{def:atoms}{Atoms}
sawine@55
    58
\newtheorem*{def:rep function}{Representation function}
sawine@55
    59
\newtheorem*{def:next}{Next function}
sawine@55
    60
\newtheorem*{def:dnf}{Disjunctive normal form}
sawine@55
    61
\newtheorem*{def:positive formulae}{Positive formulae}
sawine@55
    62
\newtheorem*{def:consq}{Logical consequences}
sawine@55
    63
\newtheorem*{def:partial automata}{Partial automata}
sawine@55
    64
sawine@55
    65
\theoremstyle{plain}
sawine@55
    66
\newtheorem{prop:vocabulary sat}{Proposition}[section]
sawine@55
    67
\newtheorem{prop:general equiv}{Proposition}[section]
sawine@55
    68
\newtheorem{prop:computation set=language}{Proposition}[section]
sawine@55
    69
sawine@55
    70
\theoremstyle{plain}
sawine@55
    71
\newtheorem{thm:model language}{Theorem}[section]
sawine@55
    72
\newtheorem{cor:mod=model language}{Corollary}[thm:model language]
sawine@55
    73
\newtheorem{cor:mod=program language}[cor:mod=model language]{Corollary}
sawine@55
    74
\newtheorem{thm:model checking}{Theorem}[section]
sawine@55
    75
\newtheorem{lem:dnf}{Lemma}[section]
sawine@55
    76
\newtheorem{lem:consq}[lem:dnf]{Lemma}
sawine@55
    77
sawine@55
    78
\title[Algorithmic Verification]{Algorithmic Verification of Reactive Systems}
sawine@55
    79
\author{Eugen Sawin}
sawine@55
    80
\institute[University of Freiburg]
sawine@55
    81
{ 
sawine@55
    82
  Research Group for Foundations in Artificial Intelligence\\
sawine@55
    83
  Computer Science Department\\
sawine@55
    84
  University of Freiburg
sawine@55
    85
}
sawine@55
    86
\date[SS 2011]{Seminar: Automata Constructions in Model Checking}
sawine@55
    87
\subject{Model Checking}
sawine@55
    88
sawine@55
    89
\begin{document}
sawine@55
    90
\frame{\titlepage}
sawine@66
    91
sawine@55
    92
\begin{frame}
sawine@55
    93
\frametitle{Motivation}
sawine@67
    94
\framesubtitle{Model Checking 1/2}
sawine@66
    95
\begin{center}
sawine@66
    96
%\only<1>{\colorbox{black}{\makebox(35,10){\color{white} $\M \models \varphi$}}}
sawine@67
    97
\[\M \models \varphi\]
sawine@66
    98
\end{center}
sawine@66
    99
\end{frame}
sawine@66
   100
sawine@66
   101
\begin{frame}
sawine@66
   102
\frametitle{Motivation}
sawine@67
   103
\framesubtitle{Model Checking 2/2}
sawine@67
   104
\begin{center}
sawine@67
   105
Given a program $P$ and specification $\varphi$:\\
sawine@67
   106
\colorbox{black}{\makebox(150,10){\color{white} does every run of $P$ satisfy $\varphi$?}}
sawine@67
   107
\end{center}
sawine@67
   108
\end{frame}
sawine@67
   109
sawine@67
   110
\begin{frame}
sawine@67
   111
\frametitle{Motivation}
sawine@67
   112
\framesubtitle{Industry}
sawine@66
   113
\begin{figure}
sawine@66
   114
\centering
sawine@73
   115
\only<1>{
sawine@67
   116
\subfigure{\includegraphics[width=70pt,height=50pt]{images/intel.jpg}}
sawine@67
   117
\subfigure{\includegraphics[width=70pt,height=50pt]{images/airbag.jpg}}
sawine@67
   118
\subfigure{\includegraphics[width=70pt,height=50pt]{images/atc.jpg}}
sawine@73
   119
}
sawine@73
   120
\only<2>{
sawine@73
   121
\subfigure{\includegraphics[width=20pt,height=10pt]{images/intel2.jpg}}
sawine@73
   122
}
sawine@66
   123
\end{figure}
sawine@55
   124
\end{frame}
sawine@55
   125
sawine@67
   126
{
sawine@67
   127
\setbeamercolor{normal text}{bg=black, fg=white}
sawine@67
   128
\setbeamercolor{frametitle}{fg=white!30!black}
sawine@67
   129
\usebeamercolor*{normal text} 
sawine@67
   130
\usebeamercolor*{frametitle} 
sawine@67
   131
\begin{frame}
sawine@67
   132
\frametitle{Linear Temporal Logic}
sawine@70
   133
\framesubtitle{Natural language 1/2}
sawine@67
   134
\begin{center}
sawine@67
   135
``It is dark.''\\
sawine@67
   136
\visible<2->{``It is \emph{always} dark.''\\}
sawine@67
   137
\visible<3->{``It is \emph{currently} dark.''\\}
sawine@69
   138
\visible<4->{``It will \emph{necessarily} be dark.''\\}
sawine@67
   139
\visible<5->{``It is dark \emph{until} someone puts the light on.''}
sawine@67
   140
\end{center}
sawine@67
   141
\end{frame}
sawine@67
   142
}
sawine@67
   143
sawine@67
   144
\begin{frame}
sawine@67
   145
\frametitle{Linear Temporal Logic}
sawine@70
   146
\framesubtitle{Natural language 2/2}
sawine@67
   147
\begin{center}
sawine@67
   148
\only<1->{
sawine@67
   149
\color{white}
sawine@67
   150
\colorbox{black}{\makebox(50,10){It is dark}} \colorbox{orange}{\makebox(30,10){until}} \colorbox{black!30}{\makebox(50,10){there is light}}\\
sawine@67
   151
\visible<2->{
sawine@67
   152
\colorbox{black}{\makebox(50,10){$p_0$}} \colorbox{orange}{\makebox(30,10){$\U$}} \colorbox{black!30}{\makebox(50,10){$p_1$}}}
sawine@67
   153
}
sawine@67
   154
\end{center}
sawine@67
   155
\end{frame}
sawine@67
   156
sawine@67
   157
\begin{frame}
sawine@67
   158
\frametitle{Linear Temporal Logic}
sawine@67
   159
\framesubtitle{Syntax}
sawine@67
   160
\begin{def:syntax}
sawine@67
   161
Let $\Prop$ be the countable set of \emph{atomic propositions}, LTL-formulae $\varphi$ are defined using following productions:
sawine@67
   162
\[\varphi ::= p \in \Prop \,|\, \neg \varphi \,|\, \varphi \lor \varphi \,|\, \X \varphi \,|\, \varphi \U \varphi\]
sawine@67
   163
\begin{itemize}
sawine@67
   164
\item $\neg, \lor$ corresponds to the Boolean \emph{negation} and \emph{disjunction}.
sawine@67
   165
\item $\X$ reads \emph{next}.
sawine@67
   166
\item $\U$ reads \emph{until}.
sawine@67
   167
\end{itemize}
sawine@67
   168
\end{def:syntax}
sawine@67
   169
\end{frame}
sawine@67
   170
sawine@67
   171
\begin{frame}
sawine@67
   172
\frametitle{Linear Temporal Logic}
sawine@67
   173
\framesubtitle{Semantics}
sawine@67
   174
\begin{def:frames}
sawine@67
   175
An LTL-\emph{frame} is a tuple $\F = (S, R)$:
sawine@67
   176
\begin{itemize}
sawine@67
   177
\item $S = \{s_i \mid i \in \N\}$ is the set of states.
sawine@67
   178
\item $R = \{(s_i, s_{i+1}) \mid i \in \N\}$ is the accessibility relation.
sawine@67
   179
\end{itemize} 
sawine@67
   180
\end{def:frames}
sawine@67
   181
sawine@67
   182
\begin{def:models}
sawine@67
   183
An LTL-\emph{model} is a tuple $\M = (\F, V)$:
sawine@67
   184
\begin{itemize}
sawine@67
   185
\item $\F$ is a \emph{frame}.
sawine@67
   186
\item $V: S \to 2^\Prop$ is a \emph{valuation function}.
sawine@67
   187
\item Intuitively we say $p \in \Prop$ is \emph{true} at time instant $i$ iff $p \in V(i)$. 
sawine@67
   188
\end{itemize}
sawine@67
   189
\end{def:models}
sawine@67
   190
\end{frame}
sawine@67
   191
sawine@67
   192
\begin{frame}
sawine@67
   193
\frametitle{Linear Temporal Logic}
sawine@67
   194
\framesubtitle{Model Example}
sawine@67
   195
\begin{figure}
sawine@67
   196
\centering
sawine@67
   197
\begin{tikzpicture}[shorten >=1pt, node distance=2.5cm, auto, semithick, >=stealth   
sawine@67
   198
    ,accepting/.style={fill, gray!50!black, text=white}]
sawine@67
   199
\node[state, initial, initial text=] (s_0) {$\{p_0\}$};
sawine@67
   200
\path (s_0) [late options={label=below:$s_0$}];
sawine@67
   201
\node[state] (s_1) [right of= s_0] {$\{p_0, p_2\}$};
sawine@67
   202
\path (s_1) [late options={label=below:$s_1$}];
sawine@67
   203
\node[state] (s_2) [right of= s_1] {$\{p_1\}$};
sawine@67
   204
\path (s_2) [late options={label=below:$s_2$}];
sawine@67
   205
\node[state] (s_i) [right of= s_2] {$\{p_1\}$};
sawine@67
   206
\path (s_i) [late options={label=below:$s_i$}];
sawine@67
   207
\path[->] 
sawine@67
   208
(s_0) edge node {$R$} (s_1) 
sawine@67
   209
(s_1) edge node {$R$} (s_2);
sawine@67
   210
\path[dashed,->] 
sawine@67
   211
(s_2) edge node {$R$} (s_i); 
sawine@67
   212
\end{tikzpicture}
sawine@67
   213
\end{figure}
sawine@67
   214
\end{frame}
sawine@67
   215
sawine@67
   216
\begin{frame}
sawine@67
   217
\frametitle{Linear Temporal Logic}
sawine@67
   218
\framesubtitle{Satisfiability}
sawine@67
   219
\begin{def:satisfiability}
sawine@67
   220
A model $\M = (\F, V)$ \emph{satisfies} a formula $\varphi$ at time instant $i$ is denoted by $\M,i \models \varphi$:
sawine@67
   221
\begin{itemize}
sawine@67
   222
\item $\M,i \models p$ for $p \in \Prop \iff p \in V(i)$
sawine@67
   223
\item $\M,i \models \neg \varphi \iff$ not $\M,i \models \varphi$
sawine@67
   224
\item $\M,i \models \varphi \lor \psi \iff \M,i \models \varphi$ or $\M,i \models \psi$
sawine@67
   225
\item $\M,i \models \X \varphi \iff \M,i+1 \models \varphi$
sawine@67
   226
\item $\M,i \models \varphi \U \psi \iff \exists{k \geq i}: \M,k \models \psi$ and $\forall{i \leq j < k}: \M,j \models\varphi$
sawine@67
   227
\end{itemize}
sawine@67
   228
\end{def:satisfiability}
sawine@67
   229
\end{frame}
sawine@67
   230
sawine@55
   231
\begin{frame}
sawine@70
   232
\frametitle{Reactive Systems}
sawine@70
   233
\framesubtitle{Infinite inputs}
sawine@71
   234
\begin{center}
sawine@66
   235
\begin{figure}
sawine@71
   236
\setcounter{subfigure}{0} 
sawine@71
   237
\subfigure[Terminating program]{
sawine@70
   238
\begin{tikzpicture}[shorten >=1pt, node distance=1.5cm, semithick, >=stealth   
sawine@70
   239
    ,accepting/.style={fill, gray!50!black, text=white}]
sawine@71
   240
\node[state, initial, initial text=$input$] (p) {$P$};
sawine@71
   241
\coordinate (b) at (1,0);
sawine@70
   242
        %\coordinate (b) at ($(a)+1/2*(3,3)$);
sawine@71
   243
\draw (p) edge[->] node[right] {$\hspace{8pt}output$} (b);
sawine@70
   244
%\draw[->] (p) -- (b);
sawine@70
   245
\end{tikzpicture}
sawine@70
   246
}
sawine@71
   247
\hspace{10pt}
sawine@71
   248
\visible<2>{\subfigure[Reactive program]{
sawine@66
   249
\begin{tikzpicture}[shorten >=1pt, node distance=1.5cm, semithick, >=stealth   
sawine@66
   250
    ,accepting/.style={fill, gray!50!black, text=white}]
sawine@71
   251
\node[state, initial, initial text=$event$] (p) {$RP$};
sawine@71
   252
\coordinate (b) at (1.1,0);
sawine@71
   253
        %\coordinate (b) at ($(a)+1/2*(3,3)$);
sawine@71
   254
\path[->]
sawine@71
   255
(p) edge [loop right] node {$action$} ();
sawine@66
   256
\end{tikzpicture}
sawine@71
   257
}}
sawine@66
   258
\end{figure}
sawine@71
   259
\end{center}
sawine@55
   260
\end{frame}
sawine@55
   261
sawine@55
   262
\begin{frame}
sawine@56
   263
\frametitle{Automata}
sawine@59
   264
\framesubtitle{Example 1/2}
sawine@58
   265
\begin{figure}
sawine@58
   266
\centering
sawine@60
   267
\only<-3>{
sawine@58
   268
\begin{tikzpicture}[shorten >=1pt, node distance=2cm, auto, semithick, >=stealth
sawine@58
   269
    %every state/.style={fill, draw=none, gray, text=white},
sawine@58
   270
    ,accepting/.style={fill, gray!50!black, text=white}
sawine@58
   271
    %initial/.style ={gray, text=white}]%,  thick]
sawine@58
   272
    ]
sawine@58
   273
\node[state,initial, initial text=] (q_0) {$q_0$};
sawine@58
   274
\node[state] (q_1) [above right of= q_0] {$q_1$};
sawine@58
   275
\node[state,accepting](q_2) [below right of= q_1] {$q_2$};
sawine@58
   276
\path[->] 
sawine@58
   277
(q_0) edge node {$a$} (q_1)
sawine@58
   278
  edge [loop above] node {$b$} ()
sawine@58
   279
(q_1) edge node {$b$} (q_2)
sawine@58
   280
  edge [loop above] node {$a$} ()
sawine@58
   281
(q_2) %edge node {$a$} (q_1)
sawine@58
   282
  edge node {$b$} (q_0);
sawine@58
   283
\draw[->] (q_2) .. controls +(up:1cm) and +(right:1cm) .. node[above] {$a$} (q_1);
sawine@60
   284
\end{tikzpicture}\\
sawine@60
   285
\vspace{10pt}
sawine@60
   286
\visible<2-3>{$w_1 = \overline{bbaa} \implies \rho_1 = q_0q_0\overline{q_0q_1q_1q_2}$}\\
sawine@60
   287
\visible<3>{$w_2 = bb\overline{ab} \implies \rho_2 = q_0q_0\overline{q_1q_2}$}\\
sawine@60
   288
\vspace{10pt}
sawine@60
   289
\visible<4>{Accepts all inputs with infinite occurrences of $ab$.}
sawine@58
   290
}
sawine@58
   291
sawine@60
   292
\only<4>{
sawine@58
   293
\begin{tikzpicture}[shorten >=1pt, node distance=2cm, auto, semithick, >=stealth
sawine@58
   294
    %every state/.style={fill, draw=none, gray, text=white},
sawine@58
   295
    ,accepting/.style={fill, gray!50!black, text=white}
sawine@58
   296
    %initial/.style ={gray, text=white}]%,  thick]
sawine@58
   297
    ]
sawine@58
   298
\node[state,initial, initial text=] (q_0) {$q_0$};
sawine@58
   299
\node[state] (q_1) [above right of= q_0] {$q_1$};
sawine@58
   300
\node[state,accepting](q_2) [below right of= q_1] {$q_2$};
sawine@58
   301
\path[->] 
sawine@58
   302
(q_0) 
sawine@58
   303
  edge [loop above] node {$b$} ()
sawine@58
   304
(q_1) 
sawine@58
   305
  edge [loop above] node {$a$} ()
sawine@58
   306
(q_2) %edge node {$a$} (q_1)
sawine@58
   307
  edge node {$b$} (q_0);
sawine@58
   308
\color{green}
sawine@58
   309
\path[->] 
sawine@58
   310
(q_0) edge node {$a$} (q_1) 
sawine@58
   311
(q_1) edge node {$b$} (q_2);
sawine@58
   312
\draw[->] (q_2) .. controls +(up:1cm) and +(right:1cm) .. node[above] {$a$} (q_1);
sawine@59
   313
\end{tikzpicture}\\
sawine@58
   314
\color{black}
sawine@60
   315
\vspace{10pt}
sawine@60
   316
\visible<2->{$w_1 = \overline{\textcolor{green}{b}ba\textcolor{green}{a}} \implies \rho_1 = q_0q_0\overline{q_0q_1q_1\textcolor{green}{q_2}}$}\\
sawine@60
   317
\visible<3->{$w_2 = bb\overline{\textcolor{green}{ab}} \implies \rho_2 = q_0q_0\overline{q_1\textcolor{green}{q_2}}$}\\
sawine@60
   318
\vspace{10pt}
sawine@60
   319
\visible<4>{Accepts all inputs with infinite occurrences of $ab$.}
sawine@58
   320
}
sawine@58
   321
%Automaton $\A_1$
sawine@58
   322
\end{figure}
sawine@58
   323
\end{frame}
sawine@58
   324
sawine@58
   325
\begin{frame}
sawine@58
   326
\frametitle{Automata}
sawine@59
   327
\framesubtitle{Example 2/2 (Complement)}
sawine@58
   328
\begin{figure}
sawine@58
   329
\centering
sawine@60
   330
\only<1>{
sawine@58
   331
  \subfigure
sawine@58
   332
            {
sawine@58
   333
              \begin{tikzpicture}[shorten >=1pt, node distance=2cm, auto, semithick, >=stealth
sawine@58
   334
                  %every state/.style={fill, draw=none, gray, text=white},
sawine@58
   335
                  ,accepting/.style={fill, gray!50!black, text=white}
sawine@58
   336
                  %initial/.style ={gray, text=white}]%,  thick]
sawine@58
   337
                ]
sawine@58
   338
                \node[state,initial, initial text=, accepting] (q_0) {$q_0$};
sawine@58
   339
                \node[state, accepting] (q_1) [above right of= q_0] {$q_1$};
sawine@58
   340
                \node[state](q_2) [below right of= q_1] {$q_2$};
sawine@58
   341
                \path[->] 
sawine@58
   342
                (q_0) edge node {$a$} (q_1)
sawine@58
   343
                edge [loop above] node {$b$} ()
sawine@58
   344
                (q_1) edge node {$b$} (q_2)
sawine@58
   345
                edge [loop above] node {$a$} ()
sawine@58
   346
                (q_2) %edge node {$a$} (q_1)
sawine@58
   347
                edge node {$b$} (q_0);
sawine@58
   348
                \draw[->] (q_2) .. controls +(up:1cm) and +(right:1cm) .. node[above] {$a$} (q_1);
sawine@58
   349
              \end{tikzpicture}
sawine@58
   350
            }
sawine@58
   351
}
sawine@58
   352
\only<2>{ 
sawine@58
   353
  \subfigure
sawine@58
   354
            {
sawine@58
   355
              \begin{tikzpicture}[shorten >=1pt, node distance=2cm, auto, semithick, >=stealth
sawine@58
   356
                  %every state/.style={fill, draw=none, gray, text=white},
sawine@58
   357
                  ,accepting/.style={fill, gray!50!black, text=white}
sawine@58
   358
                  %initial/.style ={gray, text=white}]%,  thick]
sawine@58
   359
                ]
sawine@58
   360
                \node[state,initial, initial text=, accepting] (q_0) {$q_0$};
sawine@58
   361
                \node[state, accepting] (q_1) [above right of= q_0] {$q_1$};
sawine@58
   362
                \node[state](q_2) [below right of= q_1] {$q_2$};
sawine@58
   363
                \path[->] 
sawine@58
   364
                (q_0) 
sawine@58
   365
                edge [loop above] node {$b$} ()
sawine@58
   366
                (q_1) 
sawine@58
   367
                edge [loop above] node {$a$} ();                
sawine@58
   368
                \color{red}  
sawine@58
   369
                \path[->] 
sawine@58
   370
                (q_0) edge node {$a$} (q_1)
sawine@58
   371
                (q_1) edge node {$b$} (q_2)
sawine@58
   372
                (q_2) edge node {$b$} (q_0);  
sawine@58
   373
                \draw[->] (q_2) .. controls +(up:1cm) and +(right:1cm) .. node[above] {$a$} (q_1);              
sawine@58
   374
              \end{tikzpicture}  \color{red}  
sawine@58
   375
            }
sawine@58
   376
 \color{black}
sawine@58
   377
}
sawine@58
   378
\only<3->{ \setcounter{subfigure}{0} 
sawine@62
   379
  \subfigure[Complement automaton \cross]
sawine@58
   380
            {
sawine@58
   381
              \begin{tikzpicture}[shorten >=1pt, node distance=2cm, auto, semithick, >=stealth
sawine@58
   382
                  %every state/.style={fill, draw=none, gray, text=white},
sawine@58
   383
                  ,accepting/.style={fill, gray!50!black, text=white}
sawine@58
   384
                  %initial/.style ={gray, text=white}]%,  thick]
sawine@58
   385
                ]
sawine@58
   386
                \node[state,initial, initial text=, accepting] (q_0) {$q_0$};
sawine@58
   387
                \node[state, accepting] (q_1) [above right of= q_0] {$q_1$};
sawine@58
   388
                \node[state](q_2) [below right of= q_1] {$q_2$};
sawine@58
   389
                \path[->] 
sawine@58
   390
                (q_0) 
sawine@58
   391
                edge [loop above] node {$b$} ()
sawine@58
   392
                (q_1) 
sawine@58
   393
                edge [loop above] node {$a$} ();                
sawine@58
   394
                \path[->] 
sawine@58
   395
                (q_0) edge node {$a$} (q_1)
sawine@58
   396
                (q_1) edge node {$b$} (q_2)
sawine@58
   397
                (q_2) edge node {$b$} (q_0);  
sawine@58
   398
                \draw[->] (q_2) .. controls +(up:1cm) and +(right:1cm) .. node[above] {$a$} (q_1);              
sawine@58
   399
              \end{tikzpicture}  \color{red}  
sawine@58
   400
            }
sawine@58
   401
 \color{black}
sawine@58
   402
}
sawine@60
   403
%\hspace{10pt}
sawine@58
   404
\visible<3->{
sawine@62
   405
  \subfigure[Complement automaton \checkmark]
sawine@58
   406
            {
sawine@58
   407
              \label{fig:complement automaton}
sawine@58
   408
              \begin{tikzpicture}[shorten >=1pt, node distance=2cm, auto, semithick, >=stealth   
sawine@58
   409
                  ,accepting/.style={fill, gray!50!black, text=white}]
sawine@58
   410
                \node[state, initial, initial text=] (q_0) {$q_0$};
sawine@58
   411
                \node[state, accepting] (q_1) [above right of= q_0] {$q_1$};
sawine@58
   412
                \node[state, accepting](q_2) [below right of= q_1] {$q_2$};
sawine@58
   413
                \path[->] 
sawine@58
   414
                (q_0) edge node {$a$} (q_1)
sawine@58
   415
                edge node {$b$} (q_2)
sawine@58
   416
                edge [loop above] node {$a, b$} ()
sawine@58
   417
                (q_1) edge [loop above] node {$a$} ()
sawine@58
   418
                (q_2) 
sawine@58
   419
                edge [loop above] node {$b$} ();
sawine@58
   420
              \end{tikzpicture}\color{green}  
sawine@59
   421
            }\\
sawine@58
   422
\color{black}  
sawine@59
   423
\vspace{20pt}
sawine@66
   424
Accepts all inputs with finite many $ab$.
sawine@58
   425
}
sawine@58
   426
%\caption{Automata from Example \ref{ex:automaton}}
sawine@58
   427
\end{figure}
sawine@58
   428
\end{frame}
sawine@61
   429
\color{black}  
sawine@58
   430
sawine@58
   431
\begin{frame}
sawine@58
   432
\frametitle{Automata}
sawine@56
   433
\framesubtitle{Definition}
sawine@55
   434
\begin{def:buechi automata}
sawine@56
   435
A non-deterministic B\"uchi automaton is a tuple $\A = (\Sigma, S, S_0, \Delta, F)$ with:
sawine@55
   436
\begin{itemize}
sawine@57
   437
\item $\Sigma$ is a finite \emph{alphabet}.
sawine@57
   438
\item $S$ is a finite set of \emph{states}.
sawine@57
   439
\item $S_0 \subseteq S$ is the set of \emph{initial states}.
sawine@57
   440
\item $\Delta: S \times \Sigma \times S$ is a \emph{transition relation}.
sawine@57
   441
\item $F \subseteq S$ is the set of \emph{accepting states}.
sawine@55
   442
\end{itemize}
sawine@55
   443
\end{def:buechi automata}
sawine@55
   444
\end{frame}
sawine@55
   445
sawine@55
   446
\begin{frame}
sawine@56
   447
\frametitle{Automata}
sawine@56
   448
\framesubtitle{Runs}
sawine@56
   449
\begin{def:automata runs}
sawine@56
   450
Let $\A = (\Sigma, S, S_0, \Delta, F)$ be an automaton:
sawine@56
   451
\begin{itemize}
sawine@56
   452
\item A run $\rho$ of $\A$ on an infinite word $w = a_0,a_1,...$ is a sequence $\rho = s_0,s_1,...$:
sawine@56
   453
\begin{itemize}
sawine@57
   454
\item $s_0 \in S_0$.
sawine@57
   455
\item $(s_i, a_i, s_{i+1}) \in \Delta$, for all $i \geq 0$.
sawine@56
   456
\end{itemize}
sawine@57
   457
\item Alternative view of a run $\rho$ as a function $\rho : \N \to S$, with $\rho(i) = s_i$.
sawine@56
   458
\end{itemize}
sawine@56
   459
\end{def:automata runs}
sawine@66
   460
\visible<2->{\[w_1 = \overline{\textcolor{green}{b}ba\textcolor{green}{a}} \implies \rho_1 = q_0q_0\overline{q_0q_1q_1\textcolor{green}{q_2}}\]
sawine@66
   461
\[w_2 = bb\overline{\textcolor{green}{ab}} \implies \rho_2 = q_0q_0\overline{q_1\textcolor{green}{q_2}}\]}
sawine@56
   462
\end{frame}
sawine@56
   463
sawine@56
   464
\begin{frame}
sawine@56
   465
\frametitle{Automata}
sawine@56
   466
\framesubtitle{Acceptance}
sawine@56
   467
\begin{def:inf}
sawine@56
   468
Let $\A = (\Sigma, S, S_0, \Delta, F)$ be an automaton and let $\rho$ be a run of $\A$:
sawine@56
   469
\begin{itemize}
sawine@59
   470
\item $\exists^\omega$ denotes the existential quantifier for \emph{infinitely} many occurrences.
sawine@57
   471
\item $inf(\rho) = \{s \in S \mid \exists^\omega{n \in \N}: \rho(n) = s\}$.
sawine@56
   472
\end{itemize}
sawine@56
   473
\end{def:inf}
sawine@56
   474
sawine@56
   475
\begin{def:automata acceptance}
sawine@56
   476
Let $\A = (\Sigma, S, S_0, \Delta, F)$ be an automaton and let $\rho$ be a run of $\A$:
sawine@56
   477
\begin{itemize}
sawine@56
   478
\item $\rho$ is \emph{accepting} iff $inf(\rho) \cap F \neq \emptyset$.
sawine@59
   479
\item $\A$ \emph{accepts} an input word $w$ iff there exists a run $\rho$ of $\A$ on $w$, such that $\rho$ is accepting. 
sawine@56
   480
\end{itemize}
sawine@56
   481
\end{def:automata acceptance}
sawine@56
   482
\end{frame}
sawine@56
   483
sawine@56
   484
\begin{frame}
sawine@56
   485
\frametitle{Automata}
sawine@56
   486
\framesubtitle{Language}
sawine@56
   487
\begin{def:automata language}
sawine@56
   488
Let $\A = (\Sigma, S, S_0, \Delta, F)$ be an automaton:
sawine@56
   489
\begin{itemize}
sawine@57
   490
\item $L_\omega(\A) = \{w \in \Sigma^\omega \mid \A \text{ accepts } w\}$, we say $\A$ recognises language $L_\omega(\A)$.
sawine@57
   491
\item Language $L$ is \emph{B\"uchi-recognisable} iff there is an automaton $\A$ with $L = L_\omega(\A)$.
sawine@56
   492
\end{itemize}
sawine@56
   493
\end{def:automata language}
sawine@56
   494
\end{frame}
sawine@56
   495
sawine@56
   496
\begin{frame}
sawine@57
   497
\frametitle{Generalised Automata}
sawine@57
   498
\begin{def:general automata}
sawine@65
   499
A \emph{generalised B\"uchi automaton} is a tuple $\A_G = (\Sigma, S, S_0, \Delta, \{F_i\}_{i<k})$:
sawine@57
   500
\begin{itemize}
sawine@57
   501
\item $\{F_i\}$ is a finite set of sets for a given $k$.
sawine@57
   502
\item Each $F_i \subseteq S$ is a finite set of accepting states.
sawine@57
   503
\end{itemize}
sawine@57
   504
\end{def:general automata}
sawine@57
   505
sawine@57
   506
\begin{def:general acceptance}
sawine@65
   507
Let $\A_G = (\Sigma, S, S_0, \Delta, \{F_i\}_{i<k})$ be a generalised automaton and let $\rho$ be a run of $\A_G$:
sawine@57
   508
\begin{itemize}
sawine@57
   509
\item $\rho$ is \emph{accepting} iff $\forall{i < k}: inf(\rho) \cap F_i \neq \emptyset$.
sawine@65
   510
\item $\A_G$ \emph{accepts} an input word $w$ iff there exists a run $\rho$ of $\A_G$ on $w$, such that $\rho$ is accepting. 
sawine@57
   511
\end{itemize} 
sawine@57
   512
\end{def:general acceptance}
sawine@57
   513
sawine@57
   514
\begin{prop:general equiv}
sawine@65
   515
Let $\A_G = (\Sigma, S, S_0, \Delta, \{F_i\}_{i < k})$ be a generalised automaton and let $\A_i = (\Sigma, S, S_0, \Delta, F_i)$ be non-deterministic automata:
sawine@65
   516
\[L_\omega(\A_G) = \bigcap_{i < k} L_\omega(\A_i)\]
sawine@57
   517
\end{prop:general equiv}
sawine@57
   518
\end{frame}
sawine@57
   519
sawine@65
   520
\begin{frame}
sawine@68
   521
\frametitle{Automata Construction}
sawine@68
   522
\framesubtitle{Formula automata}
sawine@68
   523
\begin{center}
sawine@68
   524
Model $\M_\varphi$ for formula $\varphi$\\
sawine@68
   525
$\Downarrow$\\
sawine@68
   526
Closure $CL(\varphi)$ of $\varphi$\\
sawine@68
   527
$\Downarrow$\\
sawine@68
   528
Automaton $\A_\varphi$ for $\varphi$\\
sawine@68
   529
\vspace{20pt}
sawine@72
   530
\visible<2>{\textcolor{red}{On-the-fly methods} \`a la Gerth et al.}
sawine@68
   531
\end{center}
sawine@68
   532
\end{frame}
sawine@68
   533
sawine@68
   534
\begin{frame}
sawine@68
   535
\frametitle{Automata Construction}
sawine@72
   536
\framesubtitle{System automata 1/2}
sawine@72
   537
\begin{def:program}
sawine@72
   538
Given a program $P = (S_P, s_0, R, V)$:
sawine@72
   539
\begin{itemize}
sawine@72
   540
\begin{multicols}{2}
sawine@72
   541
\item $S$ is the set of possible states.
sawine@72
   542
\item $s_0$ is the initial state.
sawine@72
   543
\item $R : S \times \Prop \times S$ is the transition relation.
sawine@72
   544
\item $V : S \to 2^\Prop$ is a valuation function.
sawine@72
   545
\end{multicols}
sawine@72
   546
\end{itemize}
sawine@72
   547
A \emph{computation} of $P$ is a run $\rho = (V(s_0), V(s_1), ...)$. 
sawine@72
   548
\end{def:program}
sawine@72
   549
sawine@72
   550
\begin{def:program automaton}
sawine@72
   551
We construct automaton $\A_P = (\Sigma, S, S_0, \Delta, F)$ for program $P$:
sawine@72
   552
\begin{itemize}
sawine@72
   553
\begin{multicols}{2}
sawine@72
   554
\item $\Sigma = 2^\Prop$
sawine@72
   555
\item $S = S_P$
sawine@72
   556
\item $S_0 = \{s_0\}$
sawine@72
   557
\item $F = S$
sawine@72
   558
\end{multicols}
sawine@72
   559
\vspace{-1.1em}
sawine@72
   560
\item $\Delta = \{(s, V(s), s') \mid \exists{a \in \Prop}: (s, a, s') \in R\}$
sawine@72
   561
\end{itemize}
sawine@72
   562
\end{def:program automaton}
sawine@68
   563
\end{frame}
sawine@68
   564
sawine@68
   565
\begin{frame}
sawine@72
   566
\frametitle{Automata Construction}
sawine@72
   567
\framesubtitle{System automata 2/2}
sawine@72
   568
\begin{prop:computation set=language}
sawine@72
   569
Let $\A_P = (\Sigma, S, S_0, \Delta, F)$, note that $F = S$, it follows:
sawine@72
   570
\[L_\omega(\A_P) = \{\rho \mid \rho \text{ is a run of } \A_P\}\]
sawine@72
   571
\end{prop:computation set=language}
sawine@72
   572
\end{frame}
sawine@72
   573
sawine@72
   574
\begin{frame}
sawine@72
   575
\frametitle{Verification}
sawine@72
   576
\begin{center}
sawine@72
   577
Given a program $P$ and specification $\varphi$:\\
sawine@72
   578
\colorbox{black}{\makebox(150,10){\color{white}
sawine@72
   579
\only<1>{does every run of $P$ satisfy $\varphi$?}
sawine@72
   580
\only<2>{$L_\omega(\A_P) \subseteq L_\omega(\A_\varphi)$}
sawine@72
   581
\only<3>{$L_\omega(\A_P) \cap L_\omega(\A_{\neg \varphi}) = \emptyset$}}}
sawine@72
   582
\end{center}
sawine@55
   583
\end{frame}
sawine@55
   584
sawine@55
   585
\begin{frame}[allowframebreaks]
sawine@55
   586
\frametitle<presentation>{Literature}    
sawine@55
   587
\begin{thebibliography}{10}    
sawine@55
   588
sawine@72
   589
%\beamertemplatearticlebibitems
sawine@55
   590
\bibitem{ref:ltl&büchi}
sawine@55
   591
Madhavan Mukund.
sawine@55
   592
\newblock {\em Linear-Time Temporal Logic and B\"uchi Automata}.
sawine@55
   593
\newblock Winter School on Logic and Computer Science, Indian Statistical Institute, Calcutta, 1997.
sawine@55
   594
  
sawine@72
   595
%\beamertemplatearticlebibitems
sawine@55
   596
\bibitem{ref:alternating verification}
sawine@55
   597
Moshe Y. Vardi.
sawine@55
   598
\newblock {\em Alternating Automata and Program Verification}.
sawine@55
   599
\newblock Computer Science Today, Volume 1000 of Lecture Notes in Computer Science, Springer-Verlag, Berlin, 1995.
sawine@55
   600
sawine@72
   601
\bibitem{ref:on-the-fly verification} 
sawine@72
   602
Rob Gerth, Doron Peled, Moshe Y. Vardi and Pierre Wolper.
sawine@72
   603
\newblock {\em Simple On-the-fly Automatic Verification of Linear Temporal Logic}.
sawine@72
   604
\newblock Proceeding IFIO/WG6.1 Symposium on Protocol Specification, Testing and Verification, Warsaw, 1995.
sawine@72
   605
sawine@55
   606
\beamertemplatebookbibitems
sawine@55
   607
\bibitem{ref:handbook}
sawine@72
   608
Patrick Blackburn, Frank Wolter and Johan van Benthem.
sawine@55
   609
\newblock {\em Handbook of Modal Logic}.
sawine@55
   610
\newblock 3rd Edition, Elsevier, Amsterdam, Chapter 11 P. 655-720 and Chapter 17 P. 975-989, 2007.
sawine@55
   611
sawine@72
   612
\beamertemplatearticlebibitems
sawine@72
   613
\bibitem{ref:automated verification} 
sawine@72
   614
Moshe Y. Vardi.
sawine@72
   615
\newblock {\em Automated Verification: Graphs, Logic and Automata}.
sawine@72
   616
\newblock Proceeding of the International Joint Conference on Artificial Intelligence, Acapulco, 2003.
sawine@72
   617
sawine@55
   618
\end{thebibliography}
sawine@55
   619
\end{frame}
sawine@55
   620
sawine@55
   621
\end{document}