Theorem pm2.4 344

Description: Theorem *2.4 of [WhiteheadRussell] p. 106.

Assertion

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

Proof of Theorem pm2.4

Step	Hyp	Ref	Expression
1		orc 269	. 2 |- (ph -> (ph \/ ps))
2		id 59	. 2 |- ((ph \/ ps) -> (ph \/ ps))
3	1, 2	jaoi 341	1 |- ((ph \/ (ph \/ ps)) -> (ph \/ ps))

Syntax hints:   -> wi 3   \/ wo 222

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7

This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225

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