9.23 $Pa,\ Qa\vdash\exists x(Px\wedge Qx)$


\begin{displaymath}\begin{fitch}
\par
Pa \\
\par
Qa \\
\par
Pa \wedge Qa & I$\...
...par
\exists x(Px \wedge Qx) & I$\exists$\ 3,a
\par
\end{fitch} \end{displaymath}



Daniel Clemente Laboreo 2005-05-17