Theorem imim3i 64

Description: Inference adding three nested antecedents. (Contributed by NM, 19-Dec-2006.)

Hypothesis

Ref	Expression
imim3i.1	|- ( ph -> ( ps -> ch ) )

Assertion

Ref	Expression
imim3i	|- ( ( th -> ph ) -> ( ( th -> ps ) -> ( th -> ch ) ) )

Proof of Theorem imim3i

Step	Hyp	Ref	Expression
1		imim3i.1	. . 3 |- ( ph -> ( ps -> ch ) )
2	1	imim2i 16	. 2 |- ( ( th -> ph ) -> ( th -> ( ps -> ch ) ) )
3	2	a2d 29	1 |- ( ( th -> ph ) -> ( ( th -> ps ) -> ( th -> ch ) ) )

Syntax hints:   -> wi 4

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

This theorem is referenced by:  pm2.83  84  pm5.74  259  pm3.43i  472  ral2imi  2947  ceqsalt  3228  bj-bi3ant  32574  bj-ceqsalt0  32873  bj-ceqsalt1  32874  pm10.57  38570  ee33  38727