| Step | Hyp | Ref
| Expression |
| 1 | | eqcom 2198 |
. . . . 5
⊢ (𝑥 = 𝐴 ↔ 𝐴 = 𝑥) |
| 2 | | zcn 9331 |
. . . . . . 7
⊢ (𝑥 ∈ ℤ → 𝑥 ∈
ℂ) |
| 3 | 2 | div1d 8807 |
. . . . . 6
⊢ (𝑥 ∈ ℤ → (𝑥 / 1) = 𝑥) |
| 4 | 3 | eqeq2d 2208 |
. . . . 5
⊢ (𝑥 ∈ ℤ → (𝐴 = (𝑥 / 1) ↔ 𝐴 = 𝑥)) |
| 5 | 1, 4 | bitr4id 199 |
. . . 4
⊢ (𝑥 ∈ ℤ → (𝑥 = 𝐴 ↔ 𝐴 = (𝑥 / 1))) |
| 6 | | 1nn 9001 |
. . . . 5
⊢ 1 ∈
ℕ |
| 7 | | oveq2 5930 |
. . . . . . 7
⊢ (𝑦 = 1 → (𝑥 / 𝑦) = (𝑥 / 1)) |
| 8 | 7 | eqeq2d 2208 |
. . . . . 6
⊢ (𝑦 = 1 → (𝐴 = (𝑥 / 𝑦) ↔ 𝐴 = (𝑥 / 1))) |
| 9 | 8 | rspcev 2868 |
. . . . 5
⊢ ((1
∈ ℕ ∧ 𝐴 =
(𝑥 / 1)) →
∃𝑦 ∈ ℕ
𝐴 = (𝑥 / 𝑦)) |
| 10 | 6, 9 | mpan 424 |
. . . 4
⊢ (𝐴 = (𝑥 / 1) → ∃𝑦 ∈ ℕ 𝐴 = (𝑥 / 𝑦)) |
| 11 | 5, 10 | biimtrdi 163 |
. . 3
⊢ (𝑥 ∈ ℤ → (𝑥 = 𝐴 → ∃𝑦 ∈ ℕ 𝐴 = (𝑥 / 𝑦))) |
| 12 | 11 | reximia 2592 |
. 2
⊢
(∃𝑥 ∈
ℤ 𝑥 = 𝐴 → ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℕ 𝐴 = (𝑥 / 𝑦)) |
| 13 | | risset 2525 |
. 2
⊢ (𝐴 ∈ ℤ ↔
∃𝑥 ∈ ℤ
𝑥 = 𝐴) |
| 14 | | elq 9696 |
. 2
⊢ (𝐴 ∈ ℚ ↔
∃𝑥 ∈ ℤ
∃𝑦 ∈ ℕ
𝐴 = (𝑥 / 𝑦)) |
| 15 | 12, 13, 14 | 3imtr4i 201 |
1
⊢ (𝐴 ∈ ℤ → 𝐴 ∈
ℚ) |