Description: The product of two nonzero numbers is nonzero. (Contributed by NM, 30-Dec-2007)
Ref | Expression | ||
---|---|---|---|
Assertion | mulne0 | ⊢ ( ( ( 𝐴 ∈ ℂ ∧ 𝐴 ≠ 0 ) ∧ ( 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) ) → ( 𝐴 · 𝐵 ) ≠ 0 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | mulne0b | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ) → ( ( 𝐴 ≠ 0 ∧ 𝐵 ≠ 0 ) ↔ ( 𝐴 · 𝐵 ) ≠ 0 ) ) | |
2 | 1 | biimpa | ⊢ ( ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ) ∧ ( 𝐴 ≠ 0 ∧ 𝐵 ≠ 0 ) ) → ( 𝐴 · 𝐵 ) ≠ 0 ) |
3 | 2 | an4s | ⊢ ( ( ( 𝐴 ∈ ℂ ∧ 𝐴 ≠ 0 ) ∧ ( 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) ) → ( 𝐴 · 𝐵 ) ≠ 0 ) |