Theorem bnj291

Description: /\ -manipulation. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

	Ref	Expression
Assertion	bnj291	|- ( ( ph /\ ps /\ ch /\ th ) <-> ( ( ph /\ ch /\ th ) /\ ps ) )

Proof

Step	Hyp	Ref	Expression
1		bnj290	|- ( ( ph /\ ps /\ ch /\ th ) <-> ( ph /\ ch /\ th /\ ps ) )
2		df-bnj17	|- ( ( ph /\ ch /\ th /\ ps ) <-> ( ( ph /\ ch /\ th ) /\ ps ) )
3	1 2	bitri	|- ( ( ph /\ ps /\ ch /\ th ) <-> ( ( ph /\ ch /\ th ) /\ ps ) )