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Theorem neeq2 2414
Description: Equality theorem for inequality. (Contributed by NM, 19-Nov-1994.)
Assertion
Ref Expression
neeq2 (𝐴 = 𝐵 → (𝐶𝐴𝐶𝐵))

Proof of Theorem neeq2
StepHypRef Expression
1 eqeq2 2239 . . 3 (𝐴 = 𝐵 → (𝐶 = 𝐴𝐶 = 𝐵))
21notbid 671 . 2 (𝐴 = 𝐵 → (¬ 𝐶 = 𝐴 ↔ ¬ 𝐶 = 𝐵))
3 df-ne 2401 . 2 (𝐶𝐴 ↔ ¬ 𝐶 = 𝐴)
4 df-ne 2401 . 2 (𝐶𝐵 ↔ ¬ 𝐶 = 𝐵)
52, 3, 43bitr4g 223 1 (𝐴 = 𝐵 → (𝐶𝐴𝐶𝐵))
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wb 105   = wceq 1395  wne 2400
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 617  ax-in2 618  ax-5 1493  ax-gen 1495  ax-4 1556  ax-17 1572  ax-ext 2211
This theorem depends on definitions:  df-bi 117  df-cleq 2222  df-ne 2401
This theorem is referenced by:  neeq2i  2416  neeq2d  2419  disji2  4075  fodjuomnilemdc  7322  netap  7451  2oneel  7453  2omotaplemap  7454  2omotaplemst  7455  exmidapne  7457  xrlttri3  10005  hashdmprop2dom  11079  fun2dmnop0  11082  isnzr2  14163  umgrvad2edg  16024  3dom  16411  neapmkv  16496  neap0mkv  16497  ltlenmkv  16498
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