Theorem pm5.11g

A general instance of Theorem *5.11 of [WhiteheadRussell] p. 123. (Contributed by NM, 3-Jan-2005.)

Conclusion
\( \vdash (\varphi \rightarrow \psi) \vee (\neg \varphi \rightarrow \chi) \)
Proof
pm2.5g
orri _