Theorem pm2.43b

Description: Inference absorbing redundant antecedent. (Contributed by NM, 31-Oct-1995)

	Ref	Expression
Hypothesis	pm2.43b.1	|- ( ps -> ( ph -> ( ps -> ch ) ) )
Assertion	pm2.43b	|- ( ph -> ( ps -> ch ) )

Proof

Step	Hyp	Ref	Expression
1		pm2.43b.1	|- ( ps -> ( ph -> ( ps -> ch ) ) )
2	1	pm2.43a	|- ( ps -> ( ph -> ch ) )
3	2	com12	|- ( ph -> ( ps -> ch ) )