ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  neeq2 GIF version

Theorem neeq2 2426
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 2242 . . 3 (𝐴 = 𝐵 → (𝐶 = 𝐴𝐶 = 𝐵))
21notbid 673 . 2 (𝐴 = 𝐵 → (¬ 𝐶 = 𝐴 ↔ ¬ 𝐶 = 𝐵))
3 df-ne 2413 . 2 (𝐶𝐴 ↔ ¬ 𝐶 = 𝐴)
4 df-ne 2413 . 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 1398  wne 2412
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 1496  ax-gen 1498  ax-4 1559  ax-17 1575  ax-ext 2214
This theorem depends on definitions:  df-bi 117  df-cleq 2225  df-ne 2413
This theorem is referenced by:  neeq2i  2428  neeq2d  2431  disji2  4101  fodjuomnilemdc  7435  netap  7568  2oneel  7570  2omotaplemap  7571  2omotaplemst  7572  exmidapne  7574  xrlttri3  10130  hashdmprop2dom  11216  fun2dmnop0  11222  isnzr2  14329  umgrvad2edg  16206  eupth2lem3lem4fi  16468  3dom  16762  qdiff  16833  neapmkv  16854  neap0mkv  16855  ltlenmkv  16856
  Copyright terms: Public domain W3C validator