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| Mirrors > Home > ILE Home > Th. List > neeq2 | GIF version | ||
| Description: Equality theorem for inequality. (Contributed by NM, 19-Nov-1994.) | 
| Ref | Expression | 
|---|---|
| neeq2 | ⊢ (𝐴 = 𝐵 → (𝐶 ≠ 𝐴 ↔ 𝐶 ≠ 𝐵)) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | eqeq2 2206 | . . 3 ⊢ (𝐴 = 𝐵 → (𝐶 = 𝐴 ↔ 𝐶 = 𝐵)) | |
| 2 | 1 | notbid 668 | . 2 ⊢ (𝐴 = 𝐵 → (¬ 𝐶 = 𝐴 ↔ ¬ 𝐶 = 𝐵)) | 
| 3 | df-ne 2368 | . 2 ⊢ (𝐶 ≠ 𝐴 ↔ ¬ 𝐶 = 𝐴) | |
| 4 | df-ne 2368 | . 2 ⊢ (𝐶 ≠ 𝐵 ↔ ¬ 𝐶 = 𝐵) | |
| 5 | 2, 3, 4 | 3bitr4g 223 | 1 ⊢ (𝐴 = 𝐵 → (𝐶 ≠ 𝐴 ↔ 𝐶 ≠ 𝐵)) | 
| Colors of variables: wff set class | 
| Syntax hints: ¬ wn 3 → wi 4 ↔ wb 105 = wceq 1364 ≠ wne 2367 | 
| 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 615 ax-in2 616 ax-5 1461 ax-gen 1463 ax-4 1524 ax-17 1540 ax-ext 2178 | 
| This theorem depends on definitions: df-bi 117 df-cleq 2189 df-ne 2368 | 
| This theorem is referenced by: neeq2i 2383 neeq2d 2386 disji2 4026 fodjuomnilemdc 7210 netap 7321 2oneel 7323 2omotaplemap 7324 2omotaplemst 7325 exmidapne 7327 xrlttri3 9872 isnzr2 13740 neapmkv 15712 neap0mkv 15713 ltlenmkv 15714 | 
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