Metamath Proof Explorer

Theorem bnj658

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

Ref Expression
Assertion bnj658 
|- ( ( ph /\ ps /\ ch /\ th ) -> ( ph /\ ps /\ ch ) )

Proof

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