Theorem neeq2 2434

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 2248	. . 3 |- ( A = B -> ( C = A <-> C = B ) )
2	1	notbid 677	. 2 |- ( A = B -> ( -. C = A <-> -. C = B ) )
3		df-ne 2421	. 2 |- ( C =/= A <-> -. C = A )
4		df-ne 2421	. 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 1402   =/= wne 2420

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 623  ax-in2 624  ax-5 1500  ax-gen 1502  ax-4 1563  ax-17 1579  ax-ext 2220

This theorem depends on definitions:  df-bi 117  df-cleq 2231  df-ne 2421

This theorem is referenced by:  neeq2i  2436  neeq2d  2439  disji2  4117  fodjuomnilemdc  7474  netap  7610  2oneel  7612  2omotaplemap  7613  2omotaplemst  7614  exmidapne  7616  xrlttri3  10178  hashdmprop2dom  11274  fun2dmnop0  11280  isnzr2  14464  umgrvad2edg  16366  eupth2lem3lem4fi  16628  3dom  16932  qdiff  17003  neapmkv  17023  neap0mkv  17024  ltlenmkv  17025