Theorem 3com12

Commutation in antecedent. Swap 1st and 2nd. (Contributed by NM, 28-Jan-1996.) (Proof shortened by Andrew Salmon, 13-May-2011.) (Proof shortened by Wolf Lammen, 22-Jun-2022.)

Hypothesis
3exp.1
\( \vdash \varphi \wedge \psi \wedge \chi \rightarrow \theta \)
Conclusion
\( \vdash \psi \wedge \varphi \wedge \chi \rightarrow \theta \)
Proof
3exp.1
3exp _
3imp21 _