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 ) |