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Description: A ratio is zero iff the numerator is zero. (Contributed by Mario Carneiro, 27-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | div1d.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℂ ) | |
| divcld.2 | ⊢ ( 𝜑 → 𝐵 ∈ ℂ ) | ||
| divcld.3 | ⊢ ( 𝜑 → 𝐵 ≠ 0 ) | ||
| Assertion | divne0bd | ⊢ ( 𝜑 → ( 𝐴 ≠ 0 ↔ ( 𝐴 / 𝐵 ) ≠ 0 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | div1d.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℂ ) | |
| 2 | divcld.2 | ⊢ ( 𝜑 → 𝐵 ∈ ℂ ) | |
| 3 | divcld.3 | ⊢ ( 𝜑 → 𝐵 ≠ 0 ) | |
| 4 | divne0b | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) → ( 𝐴 ≠ 0 ↔ ( 𝐴 / 𝐵 ) ≠ 0 ) ) | |
| 5 | 1 2 3 4 | syl3anc | ⊢ ( 𝜑 → ( 𝐴 ≠ 0 ↔ ( 𝐴 / 𝐵 ) ≠ 0 ) ) |