Natural deduction proof tree minimal working example

\documentclass[12pt]{article}
\usepackage{bussproofs}

\begin{document}

\begin{prooftree}
            \AxiomC{(given)}
        \alwaysNoLine
        \UnaryInfC{$A \rightarrow B$}
                    \AxiomC{(given)}
                \UnaryInfC{$B \rightarrow C$}
                    \AxiomC{(axiom)}
                \UnaryInfC{$(W)$}
            \alwaysSingleLine
            \BinaryInfC{$A \rightarrow (B \rightarrow C)$}
                \AxiomC{(axiom)}
            \alwaysNoLine
            \UnaryInfC{$(I)$}
        \alwaysSingleLine
        \BinaryInfC{$(A \rightarrow B) \rightarrow (A \rightarrow C)$}
    \BinaryInfC{$A \rightarrow C$}
\end{prooftree}

\end{document}