Theorem pm5.501 593

Description: Theorem *5.501 of [WhiteheadRussell] p. 125.

Assertion

Ref	Expression
pm5.501	|- (ph -> (ps <-> (ph <-> ps)))

Proof of Theorem pm5.501

Step	Hyp	Ref	Expression
1		ibib 588	. 2 |- ((ph -> ps) <-> (ph -> (ph <-> ps)))
2	1	pm5.74ri 585	1 |- (ph -> (ps <-> (ph <-> ps)))

Syntax hints:   -> wi 3   <-> wb 146

This theorem is referenced by:  pm5.1 674  tbt 718  biass 742

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-an 225

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