\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{Julia22} \pdfinfo{ /Title (probability-theory.pdf) /Creator (Cheatography) /Author (Julia22) /Subject (Probability Theory 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}{E629A7} \definecolor{LightBackground}{HTML}{FDF1F9} \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{Probability Theory Cheat Sheet}}}} \\ \normalsize{by \textcolor{DarkBackground}{Julia22} via \textcolor{DarkBackground}{\uline{cheatography.com/191398/cs/39786/}}} \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}Julia22 \\ \uline{cheatography.com/julia22} \\ \end{tabulary} \vfill \columnbreak \begin{tabulary}{5.8cm}{L} \SetRowColor{FootBackground} \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}} \\ \vspace{-2pt}Not Yet Published.\\ Updated 15th August, 2023.\\ 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} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Measure Theory}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{{\bf{Classes of sets}}} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{{\emph{Definition1.1}}({\bf{σ-algebra}}):A class of sets A ⊂ 2Ω if it fulfils the following three conditions: (i) Ω ∈ A. (ii) A is closed under complements. (iii) A is closed under countable unions.} \tn % Row Count 6 (+ 5) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{{\emph{Defitinition1.2}}({\bf{algebra}}):A class of sets A ⊂ 2Ω is called an algebra if the following three conditions are fulfilled: (i) Ω ∈ A. (ii) A is \textbackslash{}-closed. (iii) A is ∪-closed} \tn % Row Count 10 (+ 4) % Row 3 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{{\emph{Definition 1.3}}({\bf{ring}}):A class of sets A ⊂ 2Ω is called a ring if the following three condi- tions hold: (i) ∅ ∈ A. (ii) A is \textbackslash{}-closed. (iii) A is ∪-closed. A ring is called a {\bf{σ-ring}} if it is also σ-∪-closed} \tn % Row Count 15 (+ 5) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{{\emph{Definition 1.4}}({\bf{semiring}}): A class of sets A ⊂ 2Ω is called a semiring if (i) ∅ ∈ A, (ii) for any two sets A, B ∈ A the difference set B \textbackslash{} A is a finite union of mutually disjoint sets in A, (iii) A is ∩-closed.} \tn % Row Count 20 (+ 5) % Row 5 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{{\emph{Definition 1.5}}({\bf{Dynkin-system}}):A class of sets A ⊂ 2Ω is called a λ-system (or Dynkin's λ-system) if (i) Ω ∈ A, (ii) for any two sets A, B ∈ A with A ⊂ B, the difference set B \textbackslash{} A is in A, and (iii) ⊎∞ n=1 An ∈ A for any choice of countably many pairwise disjoint sets A1, A2, . . . ∈ A.} \tn % Row Count 27 (+ 7) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{{\emph{Definition 1.6}} ({\bf{liminf \& limsup}}):Let A1, A2, . . . be subsets of Ω. The sets lim inf n→∞ An := ∞⋃ n=1 ∞⋂ m=n Am and lim sup n→∞ An := ∞⋂ n=1 ∞⋃ m=n Am are called limes inferior and limes superior, respectively, of the sequence (An)n∈N.} \tn % Row Count 33 (+ 6) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Measure Theory (cont)}} \tn % Row 7 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{{\emph{Theorem 1.1}}({\bf{Intersection of classes of sets}}):Let I be an arbitrary index set, and assume that Ai is a σ-algebra for every i ∈ I. Hence the intersection AI := \{A ⊂ Ω : A ∈ Ai for every i ∈ I\} = ⋂ i∈I Ai is a σ-algebra. The analogous statement holds for rings, σ-rings, algebras and λ- systems. However, it fails for semirings} \tn % Row Count 7 (+ 7) % Row 8 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{{\emph{Theorem 1.2}} ({\bf{Generated σ-algebra}}):Let E ⊂ 2Ω . Then there exists a smallest σ-algebra σ(E) with E ⊂ σ(E): σ(E) := ⋂ A⊂2Ω is a σ-algebra A⊃E A.} \tn % Row Count 11 (+ 4) % Row 9 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{{\emph{Theorem 1.3}}({\bf{∩-closed λ-system}}):Let D ⊂ 2Ω be a λ-system. Then D is a π-system ⇐⇒ D is a σ-algebra.} \tn % Row Count 14 (+ 3) % Row 10 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{{\emph{Theorem 1.4}}({\bf{Dynkin's π-λ theorem}}): If E ⊂ 2Ω is a π-system, then σ(E) = δ(E).} \tn % Row Count 16 (+ 2) % Row 11 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{{\emph{Definition 1.7}}({\bf{Topology}}): Let Ω  = ∅ be an arbitrary set. A class of sets τ ⊂ Ω is called a topology on Ω if it has the following three properties: (i) ∅, Ω ∈ τ . (ii) A ∩ B ∈ τ for any A, B ∈ τ . (iii) (⋃ A∈F A) ∈ τ for any F ⊂ τ . The pair (Ω, τ ) is called a {\bf{topological space}}. The sets A ∈ τ are called open, and the sets A ⊂ Ω with Ac ∈ τ are called closed.} \tn % Row Count 25 (+ 9) % Row 12 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{{\emph{Definition 1.8}}({\bf{Borel σ-algebra}}):Let (Ω, τ ) be a topological space. The σ- algebra B(Ω) := B(Ω, τ ) := σ(τ ) that is generated by the open sets is called the Borel σ-algebra on Ω. The elements A ∈ B(Ω, τ ) are called Borel sets or Borel measurable sets.} \tn % Row Count 31 (+ 6) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Measure Theory (cont)}} \tn % Row 13 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{{\emph{Definition 1.8}} ({\bf{Trace of a class of sets}}):Let A ⊂ 2Ω be an arbitrary class of subsets of Ω and let A ∈ 2Ω \textbackslash{} \{∅\}. The class A∣ ∣A := \{A ∩ B : B ∈ A\} ⊂ 2A is called the trace of A on A or the restriction of A to A.} \tn % Row Count 5 (+ 5) \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{x{1.64241 cm} x{3.33459 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Set Functions}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Let A ⊂ 2Ω and let μ : A → {[}0, ∞{]} be a set function. We say that μ is} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} monoton & μ(A) ≤ μ(B) for any two sets A, B ∈ A with A ⊂ B, \tn % Row Count 5 (+ 3) % Row 2 \SetRowColor{LightBackground} additiv & if μ ( n⊎ i=1 Ai ) = n∑ i=1 μ(Ai) for any choice of finitely many mutually disjoint sets A1, . . . , An ∈ A with n⋃ i=1 Ai ∈ A, \tn % Row Count 11 (+ 6) % Row 3 \SetRowColor{white} σ-additive & if μ ( ∞⊎ i=1 Ai ) = ∞∑ i=1 μ(Ai) for any choice of countably many mu- tually disjoint sets A1, A2, . . . ∈ A with ∞⋃ i=1 Ai ∈ A, \tn % Row Count 17 (+ 6) % Row 4 \SetRowColor{LightBackground} subadditive & if for any choice of finitely many sets A, A1, . . . , An ∈ A with A ⊂ n⋃ i=1 Ai, we have μ(A) ≤ n∑ i=1 μ(Ai), and \tn % Row Count 22 (+ 5) % Row 5 \SetRowColor{white} \seqsplit{σ-subadditive} & if for any choice of countably many sets A, A1, A2, . . . ∈ A with A ⊂ ∞⋃ i=1 Ai, we have μ(A) ≤ ∞∑ i=1 μ(Ai) \tn % Row Count 27 (+ 5) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Let A be a semiring and let μ : A → {[}0, ∞{]} be a set function with μ(∅) = 0. μ is called a} \tn % Row Count 29 (+ 2) % Row 7 \SetRowColor{white} content & if μ is additive, \tn % Row Count 30 (+ 1) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{x{1.64241 cm} x{3.33459 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Set Functions (cont)}} \tn % Row 8 \SetRowColor{LightBackground} premeasure & if μ is σ-additive, \tn % Row Count 1 (+ 1) % Row 9 \SetRowColor{white} measure & if μ is a premeasure and A is a σ-algebra \tn % Row Count 3 (+ 2) % Row 10 \SetRowColor{LightBackground} probability measure & if μ is a measure and μ(Ω) = 1 \tn % Row Count 5 (+ 2) % Row 11 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Let A be a semiring. A content μ on A is called} \tn % Row Count 6 (+ 1) % Row 12 \SetRowColor{LightBackground} finite & if μ(A) \textless{} ∞ for every A ∈ A \tn % Row Count 8 (+ 2) % Row 13 \SetRowColor{white} σ-finite & if there exists a sequence of sets Ω1, Ω2, . . . ∈ A such that Ω = ∞⋃ n=1 Ωn and such that μ(Ωn) \textless{} ∞ for all n ∈ N. \tn % Row Count 14 (+ 6) % Row 14 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Examples} \tn % Row Count 15 (+ 1) % Row 15 \SetRowColor{white} Dirac measure & Let ω ∈ Ω and δω (A) = 1A(ω) . Then δω is a probability measure on any σ-algebra A ⊂ 2Ω . δω is called the \tn % Row Count 20 (+ 5) % Row 16 \SetRowColor{LightBackground} uniform distribution & Let Ω be a finite nonempty set. By μ(A) := \#A \#Ω for A ⊂ Ω, we define a probability measure on A = 2Ω \tn % Row Count 25 (+ 5) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} % That's all folks \end{multicols*} \end{document}