Theorem anabss5

Description: Absorption of antecedent into conjunction. (Contributed by NM, 10-May-1994) (Proof shortened by Wolf Lammen, 1-Jan-2013)

	Ref	Expression
Hypothesis	anabss5.1	|- ( ( ph /\ ( ph /\ ps ) ) -> ch )
Assertion	anabss5	|- ( ( ph /\ ps ) -> ch )

Proof

Step	Hyp	Ref	Expression
1		anabss5.1	|- ( ( ph /\ ( ph /\ ps ) ) -> ch )
2	1	anassrs	|- ( ( ( ph /\ ph ) /\ ps ) -> ch )
3	2	anabsan	|- ( ( ph /\ ps ) -> ch )