Theorem pm4.65 416

Description: Theorem *4.65 of [WhiteheadRussell] p. 120. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm4.65	|- (-. (-. ph -> ps) <-> (-. ph /\ -. ps))

Proof of Theorem pm4.65

Step	Hyp	Ref	Expression
1		pm4.61 415	1 |- (-. (-. ph -> ps) <-> (-. ph /\ -. ps))

Syntax hints:  -. wn 3   -> wi 4   <-> wb 176   /\ wa 358

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  df-an 360

This theorem is referenced by:  ioran  476