Theorem pm2.4 695

Description: Theorem *2.4 of [WhiteheadRussell] p. 106. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm2.4	|- ( ( ph \/ ( ph \/ ps ) ) -> ( ph \/ ps ) )

Proof of Theorem pm2.4

Step	Hyp	Ref	Expression
1		orc 633	. 2 |- ( ph -> ( ph \/ ps ) )
2		id 19	. 2 |- ( ( ph \/ ps ) -> ( ph \/ ps ) )
3	1, 2	jaoi 636	1 |- ( ( ph \/ ( ph \/ ps ) ) -> ( ph \/ ps ) )

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: (None)