\documentclass[10pt,a4paper]{article} % Packages \usepackage{fancyhdr} % For header and footer \usepackage{multicol} % Allows multicols in tables \usepackage{tabularx} % Intelligent column widths \usepackage{tabulary} % Used in header and footer \usepackage{hhline} % Border under tables \usepackage{graphicx} % For images \usepackage{xcolor} % For hex colours %\usepackage[utf8x]{inputenc} % For unicode character support \usepackage[T1]{fontenc} % Without this we get weird character replacements \usepackage{colortbl} % For coloured tables \usepackage{setspace} % For line height \usepackage{lastpage} % Needed for total page number \usepackage{seqsplit} % Splits long words. %\usepackage{opensans} % Can't make this work so far. Shame. Would be lovely. \usepackage[normalem]{ulem} % For underlining links % Most of the following are not required for the majority % of cheat sheets but are needed for some symbol support. \usepackage{amsmath} % Symbols \usepackage{MnSymbol} % Symbols \usepackage{wasysym} % Symbols %\usepackage[english,german,french,spanish,italian]{babel} % Languages % Document Info \author{Vipera} \pdfinfo{ /Title (automata.pdf) /Creator (Cheatography) /Author (Vipera) /Subject (Automata Cheat Sheet) } % Lengths and widths \addtolength{\textwidth}{6cm} \addtolength{\textheight}{-1cm} \addtolength{\hoffset}{-3cm} \addtolength{\voffset}{-2cm} \setlength{\tabcolsep}{0.2cm} % Space between columns \setlength{\headsep}{-12pt} % Reduce space between header and content \setlength{\headheight}{85pt} % If less, LaTeX automatically increases it \renewcommand{\footrulewidth}{0pt} % Remove footer line \renewcommand{\headrulewidth}{0pt} % Remove header line \renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit % This two commands together give roughly % the right line height in the tables \renewcommand{\arraystretch}{1.3} \onehalfspacing % Commands \newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour \newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols \newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns \newcommand{\tn}{\tabularnewline} % Required as custom column type in use % Font and Colours \definecolor{HeadBackground}{HTML}{333333} \definecolor{FootBackground}{HTML}{666666} \definecolor{TextColor}{HTML}{333333} \definecolor{DarkBackground}{HTML}{9E2020} \definecolor{LightBackground}{HTML}{F8F1F1} \renewcommand{\familydefault}{\sfdefault} \color{TextColor} % Header and Footer \pagestyle{fancy} \fancyhead{} % Set header to blank \fancyfoot{} % Set footer to blank \fancyhead[L]{ \noindent \begin{multicols}{3} \begin{tabulary}{5.8cm}{C} \SetRowColor{DarkBackground} \vspace{-7pt} {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}} } \end{tabulary} \columnbreak \begin{tabulary}{11cm}{L} \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Automata Cheat Sheet}}}} \\ \normalsize{by \textcolor{DarkBackground}{Vipera} via \textcolor{DarkBackground}{\uline{cheatography.com/128346/cs/25093/}}} \end{tabulary} \end{multicols}} \fancyfoot[L]{ \footnotesize \noindent \begin{multicols}{3} \begin{tabulary}{5.8cm}{LL} \SetRowColor{FootBackground} \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}} \\ \vspace{-2pt}Vipera \\ \uline{cheatography.com/vipera} \\ \end{tabulary} \vfill \columnbreak \begin{tabulary}{5.8cm}{L} \SetRowColor{FootBackground} \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}} \\ \vspace{-2pt}Published 11th December, 2020.\\ Updated 12th December, 2020.\\ Page {\thepage} of \pageref{LastPage}. \end{tabulary} \vfill \columnbreak \begin{tabulary}{5.8cm}{L} \SetRowColor{FootBackground} \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}} \\ \SetRowColor{white} \vspace{-5pt} %\includegraphics[width=48px,height=48px]{dave.jpeg} Measure your website readability!\\ www.readability-score.com \end{tabulary} \end{multicols}} \begin{document} \raggedright \raggedcolumns % Set font size to small. Switch to any value % from this page to resize cheat sheet text: % www.emerson.emory.edu/services/latex/latex_169.html \footnotesize % Small font. \begin{multicols*}{3} \begin{tabularx}{5.377cm}{x{2.38896 cm} x{2.58804 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{DFA (Deterministic Finite Automaton)}} \tn % Row 0 \SetRowColor{LightBackground} Automaton Representation & {\bf{M=(Q,Σ,δ,q0,F)}} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} {\bf{Q:}} Set of states & \{q0,q1,q2\} \tn % Row Count 4 (+ 2) % Row 2 \SetRowColor{LightBackground} {\bf{Σ:}} input alphabet & \{a,b\} \& ε ∉ Σ \tn % Row Count 6 (+ 2) % Row 3 \SetRowColor{white} {\bf{δ:}} transition function & δ(q,x)=q' \tn % Row Count 8 (+ 2) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{q0:}} initial state} \tn % Row Count 9 (+ 1) % Row 5 \SetRowColor{white} {\bf{F:}} set of accepting states & \{q2\} \tn % Row Count 11 (+ 2) % Row 6 \SetRowColor{LightBackground} Language of Automaton & L(M)=\{ w∈Σ* : δ*(q0,w)∈F\} \tn % Row Count 13 (+ 2) \hhline{>{\arrayrulecolor{DarkBackground}}--} \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Languages are regular if a DFA exists for that language. \newline DFA: Each state has one transition for evrey alphabet} \tn \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{x{2.38896 cm} x{2.58804 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{NFA (Non-deterministic Finite Automaton)}} \tn % Row 0 \SetRowColor{LightBackground} Formal Definition & {\bf{M=(Q,Σ,Δ,S,F)}} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} {\bf{Q:}} Set of states & \{q0,q1,q2\} \tn % Row Count 4 (+ 2) % Row 2 \SetRowColor{LightBackground} {\bf{Σ:}} input alphabet & \{a,b\} \tn % Row Count 6 (+ 2) % Row 3 \SetRowColor{white} {\bf{Δ:}} transition function & Δ(q,x)=\{q1,q2,...\} (include ε) \tn % Row Count 8 (+ 2) % Row 4 \SetRowColor{LightBackground} {\bf{S:}} initial states & \{q0\} \tn % Row Count 10 (+ 2) % Row 5 \SetRowColor{white} {\bf{F:}} set of accepting states & \{q2\} \tn % Row Count 12 (+ 2) % Row 6 \SetRowColor{LightBackground} Language of Automaton & L(M) = \{w1,w2,...,wn\} \tn % Row Count 14 (+ 2) \hhline{>{\arrayrulecolor{DarkBackground}}--} \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{NFA: Each state can have different transition with the same language output} \tn \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{NFA to DFA Conversion}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{1. Set initial state of NFA to initial state of DFA} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{2. Take the states in the DFA, and compute in the NFA what the union Δ of those states for each letter in the alphabet and add them as new states in the DFA.\{\{nl\}\}{\emph{For example if (q0,a) takes you to \{q1,q2\} add a state \{q1,q2\}. If there isn't one, the add state null}}} \tn % Row Count 8 (+ 6) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{3. Set every DFA state as accepting if it contains an accepting state from the NFA} \tn % Row Count 10 (+ 2) \hhline{>{\arrayrulecolor{DarkBackground}}-} \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{The language for the NFA (M) and DFA (M') are equivalent \{\{nl\}\} L(M)=L(M')} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{x{1.44333 cm} x{3.53367 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Properties of Regex}} \tn % Row 0 \SetRowColor{LightBackground} L1 ∪ L2 & Initial state has two ε transitions, one to L1 and one to L2 \tn % Row Count 3 (+ 3) % Row 1 \SetRowColor{white} L1L2 & L1 accept state tranitions (ε) to L2 initial state \tn % Row Count 5 (+ 2) % Row 2 \SetRowColor{LightBackground} L1* & New initial state transitions to L1 initial state. New accept state transitions (ε) from L1 accept state. Initial to accept state transition transitions (ε) and vice versa. \tn % Row Count 12 (+ 7) % Row 3 \SetRowColor{white} L1\textasciicircum{}R\textasciicircum{} (reverse) & Reverse all transitions. Make initial state accepting state and vice versa. \tn % Row Count 15 (+ 3) % Row 4 \SetRowColor{LightBackground} !(L1) Complement & Accepting states become non-accepting and vice versa \tn % Row Count 17 (+ 2) % Row 5 \SetRowColor{white} L1 ∩ L2 & !( !(L1) ∪ !(L2) ) \tn % Row Count 18 (+ 1) \hhline{>{\arrayrulecolor{DarkBackground}}--} \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{P.S. To turn multiple states to one accept state in an NFA, just add a new accept state, and add transition to the old accept states with language ε.} \tn \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{x{2.83689 cm} x{2.14011 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Intersection DFA1 ∩ DFA2}} \tn % Row 0 \SetRowColor{LightBackground} {\bf{Transitions}}\{\{nl\}\}M\textasciicircum{}1\textasciicircum{}: q1→\textasciicircum{}a\textasciicircum{}→q2 \{\{nl\}\} M\textasciicircum{}2\textasciicircum{}: p1→\textasciicircum{}a\textasciicircum{}→p2 & DFA M: (q1,p1)→\textasciicircum{}a\textasciicircum{}→(q2,p2) \tn % Row Count 4 (+ 4) % Row 1 \SetRowColor{white} {\bf{Initial State}}\{\{nl\}\}M\textasciicircum{}1\textasciicircum{}: q0 \{\{nl\}\} M\textasciicircum{}2\textasciicircum{}: p0 & DFA M: (q0,p0) \tn % Row Count 7 (+ 3) % Row 2 \SetRowColor{LightBackground} {\bf{Accept State}}\{\{nl\}\}M\textasciicircum{}1\textasciicircum{}: qi \{\{nl\}\} M\textasciicircum{}2\textasciicircum{}: pj,pk & DFA M: (qi,pj) , (qi,pk) \tn % Row Count 10 (+ 3) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{x{1.84149 cm} x{3.13551 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Regular Expressions}} \tn % Row 0 \SetRowColor{LightBackground} L(r1+r2) & = L(r1) ∪ L(r2) \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} L(r1•r2) & = L(r1)L(r2) \tn % Row Count 2 (+ 1) % Row 2 \SetRowColor{LightBackground} L(r1*) & = (L(r1))* \tn % Row Count 3 (+ 1) % Row 3 \SetRowColor{white} L(a) & = \{a\} \tn % Row Count 4 (+ 1) \hhline{>{\arrayrulecolor{DarkBackground}}--} \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Precedence: {\bf{*}} → \textasciicircum{}{\bf{+}}\textasciicircum{} → {\bf{•}} → {\bf{+}}} \tn \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{NFA to Regular Language}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{1. Transform each transition into regex (e.g. (a,b) is a+b} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{2. Remove each state one by one, until you are left with the initial and accepting state} \tn % Row Count 4 (+ 2) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{3. Resulting regular expression: {\bf{r = r1* r2(r4+r3r1*r2)*}} where: \{\{nl\}\}r1: initial → initial \{\{nl\}\}r2: initial → accepting \{\{nl\}\}r3: accepting → initial \{\{nl\}\}r4: accepting → accepting} \tn % Row Count 8 (+ 4) \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Proving Regularity with Pumping Lemma}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{Prove than an infinite language L is not regular:} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{1. Assume L is regular} \tn % Row Count 2 (+ 1) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{2. The pumping lemma should hold for L} \tn % Row Count 3 (+ 1) % Row 3 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{3. Use the pumping lemma to obtain a contradiction:} \tn % Row Count 5 (+ 2) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{~~a. Let m be the critical length for L} \tn % Row Count 6 (+ 1) % Row 5 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{~~b. Choose a particular string {\emph{w∈L}} which satisfies the length condition {\emph{|w|≥m}}} \tn % Row Count 8 (+ 2) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{~~c. Write {\emph{w=xyz}}} \tn % Row Count 9 (+ 1) % Row 7 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{~~d. Show that {\emph{w'=xy\textasciicircum{}i\textasciicircum{}z∉L for some i≠1}}} \tn % Row Count 11 (+ 2) \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} % That's all folks \end{multicols*} \end{document}