Theorem pm5.31 588

Description: Theorem *5.31 of [WhiteheadRussell] p. 125. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm5.31

Proof of Theorem pm5.31

Step	Hyp	Ref	Expression
1		pm3.21 448	. . 3
2	1	imim2d 52	. 2
3	2	imp 429	1

Syntax hints:  ->wi 4  /\wa 369

This theorem is referenced by:  bj-bary1lem1  34680

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-an 371