Theorem pm2.76 721

Description: Theorem *2.76 of [WhiteheadRussell] p. 108. (Contributed by NM, 3-Jan-2005.) (Revised by Mario Carneiro, 31-Jan-2015.)

Assertion

Ref	Expression
pm2.76	|- ( ( ph \/ ( ps -> ch ) ) -> ( ( ph \/ ps ) -> ( ph \/ ch ) ) )

Proof of Theorem pm2.76

Step	Hyp	Ref	Expression
1		orc 633	. . 3 |- ( ph -> ( ph \/ ch ) )
2	1	a1d 22	. 2 |- ( ph -> ( ( ph \/ ps ) -> ( ph \/ ch ) ) )
3		orim2 703	. 2 |- ( ( ps -> ch ) -> ( ( ph \/ ps ) -> ( ph \/ ch ) ) )
4	2, 3	jaoi 636	1 |- ( ( ph \/ ( ps -> ch ) ) -> ( ( ph \/ ps ) -> ( ph \/ ch ) ) )

Syntax hints:   -> wi 4   \/ wo 629

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 630

This theorem depends on definitions:  df-bi 110

This theorem is referenced by:  pm2.75  722  pm2.81  724  orimdidc  812  equs5or  1711