Theorem anabss7

Description: Absorption of antecedent into conjunction. (Contributed by NM, 20-Jul-1996) (Proof shortened by Wolf Lammen, 19-Nov-2013)

	Ref	Expression
Hypothesis	anabss7.1	|- ( ( ps /\ ( ph /\ ps ) ) -> ch )
Assertion	anabss7	|- ( ( ph /\ ps ) -> ch )

Proof

Step	Hyp	Ref	Expression
1		anabss7.1	|- ( ( ps /\ ( ph /\ ps ) ) -> ch )
2	1	anassrs	|- ( ( ( ps /\ ph ) /\ ps ) -> ch )
3	2	anabss4	|- ( ( ph /\ ps ) -> ch )