未定义控制序列。\end{tableau}

Question

为什么会出现错误。TeXStudio。

    \documentclass[12pt]{article}
\usepackage{pstricks}
%\usepackage{ot-tableau}
%\usepackage{ytableau}
\usepackage{forest}
\usepackage[tableaux]{prooftrees}

\begin{document}
%\maketitle
\begin{tableau}
    {
        line no sep = 1.5cm,
        just sep = 1.5cm, % Set separation of justification
        for tree = {s sep'=10mm},
        close with = \absurd
    }
    [((P \land Q) \lif R), just={Premiss}
    [\neg(P \lif (Q \lif R)), just={Negated conclusion}
    [P, just={From (2)}
    [\neg(Q \lif R), just={From (2)}
    [Q, just={From (4)}
    [\neg R, s sep=30mm, just={From (4)} %Note "s sep" to
    %spread fork below
    [\neg(P \land Q), just={Alternatives from (1)}
    [\neg P, close, just={Alternatives from (7)}
    ]
    [\neg Q, close
    ]
    ]
    [R, close]
    ]
    ]
    ]
    ]
    ]
    ]
\end{tableau}
\end{document} 

Answer 1

您需要定义（或避免）\lif和\absurd。下面，我定义\lif并避免\absurd。

\documentclass[12pt]{article}
\usepackage{pstricks}
%\usepackage{ot-tableau}
%\usepackage{ytableau}
\usepackage{forest}
\usepackage[tableaux]{prooftrees}
\newcommand*{\lif}{\ensuremath{\mathbin{\rightarrow}}}
\begin{document}
%\maketitle
\begin{tableau}
    {
        line no sep = 1.5cm,
        just sep = 1.5cm, % Set separation of justification
        for tree = {s sep'=10mm},
%         close with = \absurd
    }
    [((P \land Q) \lif R), just={Premiss}
    [\neg(P \lif (Q \lif R)), just={Negated conclusion}
    [P, just={From (2)}
    [\neg(Q \lif R), just={From (2)}
    [Q, just={From (4)}
    [\neg R, s sep=30mm, just={From (4)} %Note "s sep" to
    %spread fork below
    [\neg(P \land Q), just={Alternatives from (1)}
    [\neg P, close, just={Alternatives from (7)}
    ]
    [\neg Q, close
    ]
    ]
    [R, close]
    ]
    ]
    ]
    ]
    ]
    ]
\end{tableau}
\end{document}