Theorem pm5.62 735

Description: Theorem *5.62 of [WhiteheadRussell] p. 125. (Contributed by Roy F. Longton, 21-Jun-2005.)

Assertion

Ref	Expression
pm5.62	|- (((ph /\ ps) \/ -. ps) <-> (ph \/ -. ps))

Proof of Theorem pm5.62

Step	Hyp	Ref	Expression
1		ordir 599	. 2 |- (((ph /\ ps) \/ -. ps) <-> ((ph \/ -. ps) /\ (ps \/ -. ps)))
2		exmid 657	. 2 |- (ps \/ -. ps)
3	1, 2	mpbiran2 731	1 |- (((ph /\ ps) \/ -. ps) <-> (ph \/ -. ps))

Syntax hints:  -. wn 2   <-> wb 146   \/ wo 222   /\ wa 223

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

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