Theorem
pm5.35
Theorem *5.35 of [WhiteheadRussell] p. 125. Closed form of
2thd
. (Contributed by NM, 3-Jan-2005.)
Conclusion
\( \vdash (\varphi \rightarrow \psi) \wedge (\varphi \rightarrow \chi) \rightarrow \varphi \rightarrow (\psi \leftrightarrow \chi) \)
Proof
pm5.1
pm5.74rd
_
This is the content in the right pane.