Theorem anabss3

Description: Absorption of antecedent into conjunction. (Contributed by NM, 20-Jul-1996) (Proof shortened by Wolf Lammen, 1-Jan-2013)

	Ref	Expression
Hypothesis	anabss3.1	|- ( ( ( ph /\ ps ) /\ ps ) -> ch )
Assertion	anabss3	|- ( ( ph /\ ps ) -> ch )

Proof

Step	Hyp	Ref	Expression
1		anabss3.1	|- ( ( ( ph /\ ps ) /\ ps ) -> ch )
2	1	anasss	|- ( ( ph /\ ( ps /\ ps ) ) -> ch )
3	2	anabsan2	|- ( ( ph /\ ps ) -> ch )