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Metamath Proof Explorer

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 ) )