Theorem xchnxbi 308

Description: Replacement of a subexpression by an equivalent one. (Contributed by Wolf Lammen, 27-Sep-2014.)

Hypotheses

Ref	Expression
xchnxbi.1
xchnxbi.2

Assertion

Ref	Expression
xchnxbi

Proof of Theorem xchnxbi

Step	Hyp	Ref	Expression
1		xchnxbi.2	. . 3
2	1	notbii 296	. 2
3		xchnxbi.1	. 2
4	2, 3	bitr3i 251	1

Syntax hints:  -.wn 3  <->wb 184

This theorem is referenced by:  xchnxbir  309  ioran  490  pm5.24  894  2mo  2373  2moOLD  2374  necon1bbii  2721  nabbi  2790  psslinpr  9430  isprm2lem  14224

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