Theorem pm2.43b 52

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

Hypothesis

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

Assertion

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

Proof of Theorem pm2.43b

Step	Hyp	Ref	Expression
1		pm2.43b.1	. . 3 |- ( ps -> ( ph -> ( ps -> ch ) ) )
2	1	pm2.43a 51	. 2 |- ( ps -> ( ph -> ch ) )
3	2	com12 30	1 |- ( ph -> ( ps -> ch ) )

This proof depends on syntax axioms:   -> wi 4

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7

This theorem is used by:  trel  4236  trss  4238  elirr  4688  en2lp  4701  funfvima  5950  mapfset  6945  nnmulcl  9325  ico0  10696  ioc0  10697  bj-nn0sucALT  17004