Theorem
pm2.45
Theorem *2.45 of [WhiteheadRussell] p. 106. (Contributed by NM, 3-Jan-2005.)
Conclusion
\( \vdash \neg (\varphi \vee \psi) \rightarrow \neg \varphi \)
Proof
orc
con3i
_
This is the content in the right pane.