Theorem pm5.41 353

Description: Theorem *5.41 of [WhiteheadRussell] p. 125. (Contributed by NM, 3-Jan-2005.) (Proof shortened by Wolf Lammen, 12-Oct-2012.)

Assertion

Ref	Expression
pm5.41	|- (((ph -> ps) -> (ph -> ch)) <-> (ph -> (ps -> ch)))

Proof of Theorem pm5.41

Step	Hyp	Ref	Expression
1		imdi 352	. 2 |- ((ph -> (ps -> ch)) <-> ((ph -> ps) -> (ph -> ch)))
2	1	bicomi 193	1 |- (((ph -> ps) -> (ph -> ch)) <-> (ph -> (ps -> ch)))

Syntax hints:   -> wi 4   <-> wb 176

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 177

This theorem is referenced by: (None)