Theorem anor 489

Description: Conjunction in terms of disjunction (De Morgan's law). Theorem *4.5 of [WhiteheadRussell] p. 120. (Contributed by NM, 3-Jan-1993.) (Proof shortened by Wolf Lammen, 3-Nov-2012.)

Assertion

Ref	Expression
anor

Proof of Theorem anor

Step	Hyp	Ref	Expression
1		ianor 488	. . 3
2	1	bicomi 202	. 2
3	2	con2bii 332	1

Syntax hints:  -.wn 3  <->wb 184  \/wo 368  /\wa 369

This theorem is referenced by:  pm3.1  498  pm3.11  499  dn1  966  3anor  989  bropopvvv  6880  2wlkonot3v  24875  2spthonot3v  24876  bj-ifananb  37731

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  df-an 371