Theorem pm4.64 372

Description: Theorem *4.64 of [WhiteheadRussell] p. 120. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm4.64

Proof of Theorem pm4.64

Step	Hyp	Ref	Expression
1		df-or 370	. 2
2	1	bicomi 202	1

Syntax hints:  -.wn 3  ->wi 4  <->wb 184  \/wo 368

This theorem is referenced by:  pm4.66  420  ioran  490  dfifp3  1383  fimaxg  7787  kmlem8  8558  axgroth6  9227  dfcon2  19920  hirstL-ax3  32087  bj-ifimimb  37715  bj-ifor123g  37725

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 185  df-or 370