Theorem pm5.14 665

Description: Theorem *5.14 of [WhiteheadRussell] p. 123.

Assertion

Ref	Expression
pm5.14	|- ((ph -> ps) \/ (ps -> ch))

Proof of Theorem pm5.14

Step	Hyp	Ref	Expression
1		ax-1 4	. . . 4 |- (ps -> (ph -> ps))
2	1	con3i 98	. . 3 |- (-. (ph -> ps) -> -. ps)
3	2	pm2.21d 78	. 2 |- (-. (ph -> ps) -> (ps -> ch))
4	3	orri 231	1 |- ((ph -> ps) \/ (ps -> ch))

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

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