Metamath Proof Explorer


Theorem 3com12d

Description: Commutation in consequent. Swap 1st and 2nd. (Contributed by Jeff Hankins, 17-Nov-2009)

Ref Expression
Hypothesis 3com12d.1 φψχθ
Assertion 3com12d φχψθ

Proof

Step Hyp Ref Expression
1 3com12d.1 φψχθ
2 id χψθχψθ
3 2 3com12 ψχθχψθ
4 1 3 syl φχψθ