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Description: Only 0 is divisible by 0. Theorem 1.1(h) in ApostolNT p. 14. (Contributed by Paul Chapman, 21-Mar-2011)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0dvds | ⊢ ( 𝑁 ∈ ℤ → ( 0 ∥ 𝑁 ↔ 𝑁 = 0 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0z | ⊢ 0 ∈ ℤ | |
| 2 | divides | ⊢ ( ( 0 ∈ ℤ ∧ 𝑁 ∈ ℤ ) → ( 0 ∥ 𝑁 ↔ ∃ 𝑛 ∈ ℤ ( 𝑛 · 0 ) = 𝑁 ) ) | |
| 3 | 1 2 | mpan | ⊢ ( 𝑁 ∈ ℤ → ( 0 ∥ 𝑁 ↔ ∃ 𝑛 ∈ ℤ ( 𝑛 · 0 ) = 𝑁 ) ) |
| 4 | zcn | ⊢ ( 𝑛 ∈ ℤ → 𝑛 ∈ ℂ ) | |
| 5 | 4 | mul01d | ⊢ ( 𝑛 ∈ ℤ → ( 𝑛 · 0 ) = 0 ) |
| 6 | eqtr2 | ⊢ ( ( ( 𝑛 · 0 ) = 𝑁 ∧ ( 𝑛 · 0 ) = 0 ) → 𝑁 = 0 ) | |
| 7 | 5 6 | sylan2 | ⊢ ( ( ( 𝑛 · 0 ) = 𝑁 ∧ 𝑛 ∈ ℤ ) → 𝑁 = 0 ) |
| 8 | 7 | ancoms | ⊢ ( ( 𝑛 ∈ ℤ ∧ ( 𝑛 · 0 ) = 𝑁 ) → 𝑁 = 0 ) |
| 9 | 8 | rexlimiva | ⊢ ( ∃ 𝑛 ∈ ℤ ( 𝑛 · 0 ) = 𝑁 → 𝑁 = 0 ) |
| 10 | 3 9 | biimtrdi | ⊢ ( 𝑁 ∈ ℤ → ( 0 ∥ 𝑁 → 𝑁 = 0 ) ) |
| 11 | dvds0 | ⊢ ( 0 ∈ ℤ → 0 ∥ 0 ) | |
| 12 | 1 11 | ax-mp | ⊢ 0 ∥ 0 |
| 13 | breq2 | ⊢ ( 𝑁 = 0 → ( 0 ∥ 𝑁 ↔ 0 ∥ 0 ) ) | |
| 14 | 12 13 | mpbiri | ⊢ ( 𝑁 = 0 → 0 ∥ 𝑁 ) |
| 15 | 10 14 | impbid1 | ⊢ ( 𝑁 ∈ ℤ → ( 0 ∥ 𝑁 ↔ 𝑁 = 0 ) ) |