Theorem neeq2 2416

Description: Equality theorem for inequality. (Contributed by NM, 19-Nov-1994.)

Assertion

Ref	Expression
neeq2	|- ( A = B -> ( C =/= A <-> C =/= B ) )

Proof of Theorem neeq2

Step	Hyp	Ref	Expression
1		eqeq2 2241	. . 3 |- ( A = B -> ( C = A <-> C = B ) )
2	1	notbid 673	. 2 |- ( A = B -> ( -. C = A <-> -. C = B ) )
3		df-ne 2403	. 2 |- ( C =/= A <-> -. C = A )
4		df-ne 2403	. 2 |- ( C =/= B <-> -. C = B )
5	2, 3, 4	3bitr4g 223	1 |- ( A = B -> ( C =/= A <-> C =/= B ) )

Syntax hints:   -. wn 3   -> wi 4   <-> wb 105   = wceq 1397   =/= wne 2402

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-5 1495  ax-gen 1497  ax-4 1558  ax-17 1574  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-cleq 2224  df-ne 2403

This theorem is referenced by:  neeq2i  2418  neeq2d  2421  disji2  4080  fodjuomnilemdc  7343  netap  7473  2oneel  7475  2omotaplemap  7476  2omotaplemst  7477  exmidapne  7479  xrlttri3  10032  hashdmprop2dom  11109  fun2dmnop0  11115  isnzr2  14217  umgrvad2edg  16081  eupth2lem3lem4fi  16343  3dom  16638  qdiff  16704  neapmkv  16724  neap0mkv  16725  ltlenmkv  16726