\documentclass{standalone}

\usepackage[x11colors]{xcolor}
%
\usepackage{tikz}
\tikzset{
    event/.style={},
    smodel/.style={fill=gray!25},
    tchoice/.style={draw, circle},
    indep/.style={draw, dashed},
    proptc/.style = {-latex, dashed},
    propsm/.style = {-latex, thick},
    doubt/.style = {gray}
}
\usetikzlibrary{calc, positioning}
%
\usepackage{hyperref}
\hypersetup{
    colorlinks=true,
    linkcolor=blue,
}


\usepackage{commath}


%
% Local commands
%
\newcommand{\note}[1]{\marginpar{\scriptsize #1}}
\newcommand{\naf}{\ensuremath{\sim\!}}
\newcommand{\larr}{\ensuremath{\leftarrow}}
\newcommand{\at}[1]{\ensuremath{\!\del{#1}}}
\newcommand{\co}[1]{\ensuremath{\overline{#1}}}
\newcommand{\fml}[1]{\ensuremath{{\cal #1}}}
\newcommand{\deft}[1]{\textbf{#1}}
\newcommand{\pset}[1]{\ensuremath{\mathbb{P}\at{#1}}}
\newcommand{\ent}{\ensuremath{\lhd}}
\newcommand{\cset}[2]{\ensuremath{\set{#1,~#2}}}
\newcommand{\langof}[1]{\ensuremath{\fml{L}\at{#1}}}
\newcommand{\uset}[1]{\ensuremath{\left|{#1}\right>}}
\newcommand{\lset}[1]{\ensuremath{\left<{#1}\right|}}
\newcommand{\pr}[1]{\ensuremath{\mathrm{P}\at{#1}}}
\newcommand{\given}{\ensuremath{~\middle|~}}

\begin{document}
\begin{tikzpicture}
    \node[event] (E) {$\bot$};
    \node[tchoice, above left = of E] (a) {$a$};
    \node[smodel, above left = of a] (ab) {$ab$};
    \node[smodel, above right = of a] (ac) {$ac$};
    \node[event, below = of ab] (b) {$b$};
    \node[event, below = of ac] (c) {$c$};
    \node[event, above right = of ab] (abc) {$abc$};
    \node[indep, right = of ac] (bc) {$bc$};
    \node[tchoice, smodel, below right = of bc] (A) {$\co{a}$};
    \node[event, above = of A] (Ac) {$\co{a}c$};
    \node[event, above right = of Ac] (Abc) {$\co{a}bc$};
    % ----
    \draw[proptc] (a) to[bend left] (ab);
    \draw[proptc] (a) to[bend right] (ac);

    \draw[propsm] (ab) to[bend left] (abc);
    \draw[propsm] (ac) to[bend right] (abc);

    \draw[propsm] (A) to[bend right] (Ac);
    \draw[propsm] (A) to[bend right] (Abc);

    \draw[doubt] (ab) to[bend right] (E);
    \draw[doubt] (ac) to[bend right] (E);
    \draw[doubt] (A) to[bend left] (E);

    \draw[doubt] (ab) to[bend right] (b);
    \draw[doubt] (ac) to[bend left] (c);
    \draw[doubt] (ab) to[bend left] (a);
    \draw[doubt] (ac) to[bend right] (a);
    \draw[doubt] (c) to[bend right] (bc);
    \draw[doubt] (abc) to[bend left] (bc);
    \draw[doubt] (Abc) to (bc);
    \draw[doubt] (c) to[bend right] (Ac);
\end{tikzpicture}
    
\end{document}