Theorem impancom

Mixed importation/commutation inference. (Contributed by NM, 22-Jun-2013.)

Hypothesis
impancom.1
\( \vdash \varphi \wedge \psi \rightarrow \chi \rightarrow \theta \)
Conclusion
\( \vdash \varphi \wedge \chi \rightarrow \psi \rightarrow \theta \)
Proof
impancom.1
ex _
com23 _
imp _