Theorem anabss4

Description: Absorption of antecedent into conjunction. (Contributed by NM, 20-Jul-1996)

	Ref	Expression
Hypothesis	anabss4.1	|- ( ( ( ps /\ ph ) /\ ps ) -> ch )
Assertion	anabss4	|- ( ( ph /\ ps ) -> ch )

Proof

Step	Hyp	Ref	Expression
1		anabss4.1	|- ( ( ( ps /\ ph ) /\ ps ) -> ch )
2	1	anabss1	|- ( ( ps /\ ph ) -> ch )
3	2	ancoms	|- ( ( ph /\ ps ) -> ch )