Theorem pm2.64 429

Description: Theorem *2.64 of [WhiteheadRussell] p. 107.

Assertion

Ref	Expression
pm2.64	|- ((ph \/ ps) -> ((ph \/ -. ps) -> ph))

Proof of Theorem pm2.64

Step	Hyp	Ref	Expression
1		ax-1 4	. . 3 |- (ph -> ((ph \/ ps) -> ph))
2		orel2 252	. . 3 |- (-. ps -> ((ph \/ ps) -> ph))
3	1, 2	jaoi 341	. 2 |- ((ph \/ -. ps) -> ((ph \/ ps) -> ph))
4	3	com12 11	1 |- ((ph \/ ps) -> ((ph \/ -. ps) -> ph))

Syntax hints:  -. wn 2   -> wi 3   \/ wo 222

This theorem is referenced by:  pm4.43 431

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

Copyright terms: Public domain