Theorem pm2.31 261

Description: Theorem *2.31 of [WhiteheadRussell] p. 104.

Assertion

Ref	Expression
pm2.31	|- ((ph \/ (ps \/ ch)) -> ((ph \/ ps) \/ ch))

Proof of Theorem pm2.31

Step	Hyp	Ref	Expression
1		orass 260	. 2 |- (((ph \/ ps) \/ ch) <-> (ph \/ (ps \/ ch)))
2	1	biimpr 152	1 |- ((ph \/ (ps \/ ch)) -> ((ph \/ ps) \/ ch))

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

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