Step | Hyp | Ref
| Expression |
1 | | ax-1cn 10860 |
. 2
⊢ 1 ∈
ℂ |
2 | | cnre 10903 |
. 2
⊢ (1 ∈
ℂ → ∃𝑥
∈ ℝ ∃𝑦
∈ ℝ 1 = (𝑥 + (i
· 𝑦))) |
3 | | ax-rnegex 10873 |
. . . . 5
⊢ (𝑥 ∈ ℝ →
∃𝑧 ∈ ℝ
(𝑥 + 𝑧) = 0) |
4 | | readdcl 10885 |
. . . . . . 7
⊢ ((𝑥 ∈ ℝ ∧ 𝑧 ∈ ℝ) → (𝑥 + 𝑧) ∈ ℝ) |
5 | | eleq1 2826 |
. . . . . . 7
⊢ ((𝑥 + 𝑧) = 0 → ((𝑥 + 𝑧) ∈ ℝ ↔ 0 ∈
ℝ)) |
6 | 4, 5 | syl5ibcom 244 |
. . . . . 6
⊢ ((𝑥 ∈ ℝ ∧ 𝑧 ∈ ℝ) → ((𝑥 + 𝑧) = 0 → 0 ∈
ℝ)) |
7 | 6 | rexlimdva 3212 |
. . . . 5
⊢ (𝑥 ∈ ℝ →
(∃𝑧 ∈ ℝ
(𝑥 + 𝑧) = 0 → 0 ∈
ℝ)) |
8 | 3, 7 | mpd 15 |
. . . 4
⊢ (𝑥 ∈ ℝ → 0 ∈
ℝ) |
9 | 8 | adantr 480 |
. . 3
⊢ ((𝑥 ∈ ℝ ∧
∃𝑦 ∈ ℝ 1 =
(𝑥 + (i · 𝑦))) → 0 ∈
ℝ) |
10 | 9 | rexlimiva 3209 |
. 2
⊢
(∃𝑥 ∈
ℝ ∃𝑦 ∈
ℝ 1 = (𝑥 + (i
· 𝑦)) → 0
∈ ℝ) |
11 | 1, 2, 10 | mp2b 10 |
1
⊢ 0 ∈
ℝ |