Metamath Proof Explorer

Theorem bnj642

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

Ref Expression
Assertion bnj642 
|- ( ( ph /\ ps /\ ch /\ th ) -> ph )

Proof

Step Hyp Ref Expression
1 bnj446 
 |-  ( ( ph /\ ps /\ ch /\ th ) <-> ( ( ps /\ ch /\ th ) /\ ph ) )
2 1 simprbi 
 |-  ( ( ph /\ ps /\ ch /\ th ) -> ph )