fitch package

書き方

https://scrapbox.io/files/65d1675b19545d0025d82b6c.svg

code:fitch.tikz(tex)

\usepackage{fitch}

\begin{document}

$\begin{nd}

\hypo {1} {\forall y \neg P(y)}

\open

\hypo {2} {\exists x P(x)}

\hypo {3} {P(u)}

\have {4}{\forall y \neg P(y)} \r{1}

\have {5} {\neg P(u)} \Ae{4}

\have {6} {\bot} \ne{3,5}

\close

\have {6a} {\bot} \Ee{2,3-6}

\close

\have {7} {\neg \exists x P(x)} \ni{2-6a}

\end{nd}$

\end{document}

https://scrapbox.io/files/65d169c838dc3a0025c3e76b.svg

code:large.tikz(tex)

\usepackage{fitch}

\begin{document}

$\Large\begin{nd}

\hypo {1} {\forall y \neg P(y)}

\open

\hypo {2} {\exists x P(x)}

\hypo {3} {P(u)}

\have {4}{\forall y \neg P(y)} \r{1}

\have {5} {\neg P(u)} \Ae{4}

\have {6} {\bot} \ne{3,5}

\close

\have {6a} {\bot} \Ee{2,3-6}

\close

\have {7} {\neg \exists x P(x)} \ni{2-6a}

\end{nd}$

\end{document}