Description: A cancellation law for division. (Contributed by NM, 5-Jun-2004) (Revised by Mario Carneiro, 27-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | divcan1 | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) → ( ( 𝐴 / 𝐵 ) · 𝐵 ) = 𝐴 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | divcl | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) → ( 𝐴 / 𝐵 ) ∈ ℂ ) | |
| 2 | simp2 | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) → 𝐵 ∈ ℂ ) | |
| 3 | 1 2 | mulcomd | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) → ( ( 𝐴 / 𝐵 ) · 𝐵 ) = ( 𝐵 · ( 𝐴 / 𝐵 ) ) ) |
| 4 | divcan2 | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) → ( 𝐵 · ( 𝐴 / 𝐵 ) ) = 𝐴 ) | |
| 5 | 3 4 | eqtrd | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) → ( ( 𝐴 / 𝐵 ) · 𝐵 ) = 𝐴 ) |