Theorem simp21l

Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012)

	Ref	Expression
Assertion	simp21l	|- ( ( ta /\ ( ( ph /\ ps ) /\ ch /\ th ) /\ et ) -> ph )

Proof

Step	Hyp	Ref	Expression
1		simp1l	|- ( ( ( ph /\ ps ) /\ ch /\ th ) -> ph )
2	1	3ad2ant2	|- ( ( ta /\ ( ( ph /\ ps ) /\ ch /\ th ) /\ et ) -> ph )