Theorem pm2.38 793

Description: Theorem *2.38 of [WhiteheadRussell] p. 105. (Contributed by NM, 6-Mar-2008.)

Assertion

Ref	Expression
pm2.38	|- ( ( ps -> ch ) -> ( ( ps \/ ph ) -> ( ch \/ ph ) ) )

Proof of Theorem pm2.38

Step	Hyp	Ref	Expression
1		id 19	. 2 |- ( ( ps -> ch ) -> ( ps -> ch ) )
2	1	orim1d 777	1 |- ( ( ps -> ch ) -> ( ( ps \/ ph ) -> ( ch \/ ph ) ) )

Syntax hints:   -> wi 4   \/ wo 698

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699

This theorem depends on definitions:  df-bi 116

This theorem is referenced by:  pm2.36  794  pm2.37  795