Theorem imbi2 623

Description: Theorem *4.85 of [WhiteheadRussell] p. 122.

Assertion

Ref	Expression
imbi2	|- ((ph <-> ps) -> ((ch -> ph) <-> (ch -> ps)))

Proof of Theorem imbi2

Step	Hyp	Ref	Expression
1		ax-1 4	. 2 |- ((ph <-> ps) -> (ch -> (ph <-> ps)))
2	1	pm5.74d 584	1 |- ((ph <-> ps) -> ((ch -> ph) <-> (ch -> ps)))

Syntax hints:   -> wi 3   <-> wb 146

This theorem is referenced by:  efcn 7380

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

Copyright terms: Public domain