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Theorem neeq2 2416
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 2241 . . 3 (𝐴 = 𝐵 → (𝐶 = 𝐴𝐶 = 𝐵))
21notbid 673 . 2 (𝐴 = 𝐵 → (¬ 𝐶 = 𝐴 ↔ ¬ 𝐶 = 𝐵))
3 df-ne 2403 . 2 (𝐶𝐴 ↔ ¬ 𝐶 = 𝐴)
4 df-ne 2403 . 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 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  14204  umgrvad2edg  16068  eupth2lem3lem4fi  16330  3dom  16613  qdiff  16679  neapmkv  16699  neap0mkv  16700  ltlenmkv  16701
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