Theorem pm2.67 282

Description: Theorem *2.67 of [WhiteheadRussell] p. 107.

Assertion

Ref	Expression
pm2.67	|- (((ph \/ ps) -> ps) -> (ph -> ps))

Proof of Theorem pm2.67

Step	Hyp	Ref	Expression
1		orc 269	. 2 |- (ph -> (ph \/ ps))
2	1	imim1i 16	1 |- (((ph \/ ps) -> ps) -> (ph -> ps))

Syntax hints:   -> wi 3   \/ wo 222

This theorem is referenced by:  pm4.72 643

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

Copyright terms: Public domain