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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 2239 | . . 3 ⊢ (𝐴 = 𝐵 → (𝐶 = 𝐴 ↔ 𝐶 = 𝐵)) | |
| 2 | 1 | notbid 671 | . 2 ⊢ (𝐴 = 𝐵 → (¬ 𝐶 = 𝐴 ↔ ¬ 𝐶 = 𝐵)) |
| 3 | df-ne 2401 | . 2 ⊢ (𝐶 ≠ 𝐴 ↔ ¬ 𝐶 = 𝐴) | |
| 4 | df-ne 2401 | . 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 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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