Theorem pm2.42 343

Description: Theorem *2.42 of [WhiteheadRussell] p. 106.

Assertion

Ref	Expression
pm2.42	|- ((-. ph \/ (ph -> ps)) -> (ph -> ps))

Proof of Theorem pm2.42

Step	Hyp	Ref	Expression
1		pm2.21 76	. 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:  -. wn 2   -> 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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