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| Mirrors > Home > ILE Home > Th. List > necon3bbii | GIF version | ||
| Description: Deduction from equality to inequality. (Contributed by NM, 13-Apr-2007.) |
| Ref | Expression |
|---|---|
| necon3bbii.1 | ⊢ (𝜑 ↔ 𝐴 = 𝐵) |
| Ref | Expression |
|---|---|
| necon3bbii | ⊢ (¬ 𝜑 ↔ 𝐴 ≠ 𝐵) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | necon3bbii.1 | . . . 4 ⊢ (𝜑 ↔ 𝐴 = 𝐵) | |
| 2 | 1 | bicomi 132 | . . 3 ⊢ (𝐴 = 𝐵 ↔ 𝜑) |
| 3 | 2 | necon3abii 2403 | . 2 ⊢ (𝐴 ≠ 𝐵 ↔ ¬ 𝜑) |
| 4 | 3 | bicomi 132 | 1 ⊢ (¬ 𝜑 ↔ 𝐴 ≠ 𝐵) |
| Colors of variables: wff set class |
| Syntax hints: ¬ wn 3 ↔ 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 |
| This theorem depends on definitions: df-bi 117 df-ne 2368 |
| This theorem is referenced by: ef0lem 11825 |
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