Theorem pm2.24i 618

Description: Inference version of pm2.24 616. (Contributed by NM, 20-Aug-2001.) (Revised by Mario Carneiro, 31-Jan-2015.)

Hypothesis

Ref	Expression
pm2.24i.1	|- ph

Assertion

Ref	Expression
pm2.24i	|- ( -. ph -> ps )

Proof of Theorem pm2.24i

Step	Hyp	Ref	Expression
1		pm2.24i.1	. 2 |- ph
2		pm2.21 612	. 2 |- ( -. ph -> ( ph -> ps ) )
3	1, 2	mpi 15	1 |- ( -. ph -> ps )

Syntax hints:   -. wn 3   -> wi 4

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-in2 610

This theorem is referenced by:  niabn  962