Theorem impd

Importation deduction. (Contributed by NM, 31-Mar-1994.)

Hypothesis
impd.1
\( \vdash \varphi \rightarrow \psi \rightarrow \chi \rightarrow \theta \)
Conclusion
\( \vdash \varphi \rightarrow \psi \wedge \chi \rightarrow \theta \)
Proof
impd.1
com3l _
imp _
com12 _