Description: The negative of a nonzero number is nonzero. (Contributed by Mario Carneiro, 27-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | negidd.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℂ ) | |
| negne0d.2 | ⊢ ( 𝜑 → 𝐴 ≠ 0 ) | ||
| Assertion | negne0d | ⊢ ( 𝜑 → - 𝐴 ≠ 0 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | negidd.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℂ ) | |
| 2 | negne0d.2 | ⊢ ( 𝜑 → 𝐴 ≠ 0 ) | |
| 3 | 1 | negne0bd | ⊢ ( 𝜑 → ( 𝐴 ≠ 0 ↔ - 𝐴 ≠ 0 ) ) |
| 4 | 2 3 | mpbid | ⊢ ( 𝜑 → - 𝐴 ≠ 0 ) |