You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 

12 lines
289 B

This sequent is not provable.
Model $\mathcal{M}$:\\
\begin{minipage}{0.2\textwidth}
\begin{align*}
\mathcal{A} =& \; \{ a \}\\
P^\mathcal{M} =& \; \{ a\}
\end{align*}
\end{minipage}\\
$\mathcal{M} \models \lnot \exists x \lnot P(x)$\\
$\mathcal{M} \nmodels \forall x \lnot P(x)$