Theorem mp2d 47

Description: A double modus ponens deduction. (Contributed by NM, 23-May-2013.) (Proof shortened by Wolf Lammen, 23-Jul-2013.)

Hypotheses

Ref	Expression
mp2d.1	|- ( ph -> ps )
mp2d.2	|- ( ph -> ch )
mp2d.3	|- ( ph -> ( ps -> ( ch -> th ) ) )

Assertion

Ref	Expression
mp2d	|- ( ph -> th )

Proof of Theorem mp2d

Step	Hyp	Ref	Expression
1		mp2d.1	. 2 |- ( ph -> ps )
2		mp2d.2	. . 3 |- ( ph -> ch )
3		mp2d.3	. . 3 |- ( ph -> ( ps -> ( ch -> th ) ) )
4	2, 3	mpid 42	. 2 |- ( ph -> ( ps -> th ) )
5	1, 4	mpd 13	1 |- ( ph -> th )

Syntax hints:   -> wi 4

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

This theorem is referenced by:  fisseneq  6696  prloc  7111  axcaucvglemres  7495  bezoutlemmain  11326  coprm  11462  sqrt2irr  11480