Theorem 3impb

Importation from double to triple conjunction. (Contributed by NM, 20-Aug-1995.)

Hypothesis
3impb.1
\( \vdash \varphi \wedge (\psi \wedge \chi) \rightarrow \theta \)
Conclusion
\( \vdash \varphi \wedge \psi \wedge \chi \rightarrow \theta \)
Proof
3impb.1
exp32 _
3imp _