Theorem imdi

Distributive law for implication. Compare Theorem *5.41 of [WhiteheadRussell] p. 125. (Contributed by NM, 5-Aug-1993.)

Conclusion
\( \vdash \varphi \rightarrow \psi \rightarrow \chi \leftrightarrow (\varphi \rightarrow \psi) \rightarrow \varphi \rightarrow \chi \)
Proof
l0
ax-2
pm2.86
impbii l0 _