Theorem pm4.64 226

Description: Theorem *4.64 of [WhiteheadRussell] p. 120.

Assertion

Ref	Expression
pm4.64	|- ((-. ph -> ps) <-> (ph \/ ps))

Proof of Theorem pm4.64

Step	Hyp	Ref	Expression
1		df-or 224	. 2 |- ((ph \/ ps) <-> (-. ph -> ps))
2	1	bicomi 172	1 |- ((-. ph -> ps) <-> (ph \/ ps))

Syntax hints:  -. wn 2   -> wi 3   <-> wb 146   \/ wo 222

This theorem is referenced by:  pm4.66 236  kmlem8 4752

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