Proof of Theorem peano5nnnn
| Step | Hyp | Ref
 | Expression | 
| 1 |   | oveq1 5929 | 
. . . 4
⊢ (𝑦 = 𝑧 → (𝑦 + 1) = (𝑧 + 1)) | 
| 2 | 1 | eleq1d 2265 | 
. . 3
⊢ (𝑦 = 𝑧 → ((𝑦 + 1) ∈ 𝐴 ↔ (𝑧 + 1) ∈ 𝐴)) | 
| 3 | 2 | cbvralv 2729 | 
. 2
⊢
(∀𝑦 ∈
𝐴 (𝑦 + 1) ∈ 𝐴 ↔ ∀𝑧 ∈ 𝐴 (𝑧 + 1) ∈ 𝐴) | 
| 4 |   | ax1re 7929 | 
. . . . 5
⊢ 1 ∈
ℝ | 
| 5 |   | elin 3346 | 
. . . . . 6
⊢ (1 ∈
(𝐴 ∩ ℝ) ↔ (1
∈ 𝐴 ∧ 1 ∈
ℝ)) | 
| 6 | 5 | biimpri 133 | 
. . . . 5
⊢ ((1
∈ 𝐴 ∧ 1 ∈
ℝ) → 1 ∈ (𝐴
∩ ℝ)) | 
| 7 | 4, 6 | mpan2 425 | 
. . . 4
⊢ (1 ∈
𝐴 → 1 ∈ (𝐴 ∩
ℝ)) | 
| 8 |   | inss1 3383 | 
. . . . . 6
⊢ (𝐴 ∩ ℝ) ⊆ 𝐴 | 
| 9 |   | ssralv 3247 | 
. . . . . 6
⊢ ((𝐴 ∩ ℝ) ⊆ 𝐴 → (∀𝑦 ∈ 𝐴 (𝑦 + 1) ∈ 𝐴 → ∀𝑦 ∈ (𝐴 ∩ ℝ)(𝑦 + 1) ∈ 𝐴)) | 
| 10 | 8, 9 | ax-mp 5 | 
. . . . 5
⊢
(∀𝑦 ∈
𝐴 (𝑦 + 1) ∈ 𝐴 → ∀𝑦 ∈ (𝐴 ∩ ℝ)(𝑦 + 1) ∈ 𝐴) | 
| 11 |   | inss2 3384 | 
. . . . . . . 8
⊢ (𝐴 ∩ ℝ) ⊆
ℝ | 
| 12 | 11 | sseli 3179 | 
. . . . . . 7
⊢ (𝑦 ∈ (𝐴 ∩ ℝ) → 𝑦 ∈ ℝ) | 
| 13 |   | axaddrcl 7932 | 
. . . . . . . 8
⊢ ((𝑦 ∈ ℝ ∧ 1 ∈
ℝ) → (𝑦 + 1)
∈ ℝ) | 
| 14 | 4, 13 | mpan2 425 | 
. . . . . . 7
⊢ (𝑦 ∈ ℝ → (𝑦 + 1) ∈
ℝ) | 
| 15 |   | elin 3346 | 
. . . . . . . 8
⊢ ((𝑦 + 1) ∈ (𝐴 ∩ ℝ) ↔ ((𝑦 + 1) ∈ 𝐴 ∧ (𝑦 + 1) ∈ ℝ)) | 
| 16 | 15 | simplbi2com 1455 | 
. . . . . . 7
⊢ ((𝑦 + 1) ∈ ℝ →
((𝑦 + 1) ∈ 𝐴 → (𝑦 + 1) ∈ (𝐴 ∩ ℝ))) | 
| 17 | 12, 14, 16 | 3syl 17 | 
. . . . . 6
⊢ (𝑦 ∈ (𝐴 ∩ ℝ) → ((𝑦 + 1) ∈ 𝐴 → (𝑦 + 1) ∈ (𝐴 ∩ ℝ))) | 
| 18 | 17 | ralimia 2558 | 
. . . . 5
⊢
(∀𝑦 ∈
(𝐴 ∩ ℝ)(𝑦 + 1) ∈ 𝐴 → ∀𝑦 ∈ (𝐴 ∩ ℝ)(𝑦 + 1) ∈ (𝐴 ∩ ℝ)) | 
| 19 | 10, 18 | syl 14 | 
. . . 4
⊢
(∀𝑦 ∈
𝐴 (𝑦 + 1) ∈ 𝐴 → ∀𝑦 ∈ (𝐴 ∩ ℝ)(𝑦 + 1) ∈ (𝐴 ∩ ℝ)) | 
| 20 |   | axcnex 7926 | 
. . . . . . 7
⊢ ℂ
∈ V | 
| 21 |   | axresscn 7927 | 
. . . . . . 7
⊢ ℝ
⊆ ℂ | 
| 22 | 20, 21 | ssexi 4171 | 
. . . . . 6
⊢ ℝ
∈ V | 
| 23 | 22 | inex2 4168 | 
. . . . 5
⊢ (𝐴 ∩ ℝ) ∈
V | 
| 24 |   | eleq2 2260 | 
. . . . . . . 8
⊢ (𝑥 = (𝐴 ∩ ℝ) → (1 ∈ 𝑥 ↔ 1 ∈ (𝐴 ∩
ℝ))) | 
| 25 |   | eleq2 2260 | 
. . . . . . . . 9
⊢ (𝑥 = (𝐴 ∩ ℝ) → ((𝑦 + 1) ∈ 𝑥 ↔ (𝑦 + 1) ∈ (𝐴 ∩ ℝ))) | 
| 26 | 25 | raleqbi1dv 2705 | 
. . . . . . . 8
⊢ (𝑥 = (𝐴 ∩ ℝ) → (∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥 ↔ ∀𝑦 ∈ (𝐴 ∩ ℝ)(𝑦 + 1) ∈ (𝐴 ∩ ℝ))) | 
| 27 | 24, 26 | anbi12d 473 | 
. . . . . . 7
⊢ (𝑥 = (𝐴 ∩ ℝ) → ((1 ∈ 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥) ↔ (1 ∈ (𝐴 ∩ ℝ) ∧ ∀𝑦 ∈ (𝐴 ∩ ℝ)(𝑦 + 1) ∈ (𝐴 ∩ ℝ)))) | 
| 28 | 27 | elabg 2910 | 
. . . . . 6
⊢ ((𝐴 ∩ ℝ) ∈ V →
((𝐴 ∩ ℝ) ∈
{𝑥 ∣ (1 ∈ 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥)} ↔ (1 ∈ (𝐴 ∩ ℝ) ∧ ∀𝑦 ∈ (𝐴 ∩ ℝ)(𝑦 + 1) ∈ (𝐴 ∩ ℝ)))) | 
| 29 |   | nntopi.n | 
. . . . . . 7
⊢ 𝑁 = ∩
{𝑥 ∣ (1 ∈ 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥)} | 
| 30 |   | intss1 3889 | 
. . . . . . 7
⊢ ((𝐴 ∩ ℝ) ∈ {𝑥 ∣ (1 ∈ 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥)} → ∩ {𝑥 ∣ (1 ∈ 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥)} ⊆ (𝐴 ∩ ℝ)) | 
| 31 | 29, 30 | eqsstrid 3229 | 
. . . . . 6
⊢ ((𝐴 ∩ ℝ) ∈ {𝑥 ∣ (1 ∈ 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥)} → 𝑁 ⊆ (𝐴 ∩ ℝ)) | 
| 32 | 28, 31 | biimtrrdi 164 | 
. . . . 5
⊢ ((𝐴 ∩ ℝ) ∈ V →
((1 ∈ (𝐴 ∩
ℝ) ∧ ∀𝑦
∈ (𝐴 ∩
ℝ)(𝑦 + 1) ∈
(𝐴 ∩ ℝ)) →
𝑁 ⊆ (𝐴 ∩
ℝ))) | 
| 33 | 23, 32 | ax-mp 5 | 
. . . 4
⊢ ((1
∈ (𝐴 ∩ ℝ)
∧ ∀𝑦 ∈
(𝐴 ∩ ℝ)(𝑦 + 1) ∈ (𝐴 ∩ ℝ)) → 𝑁 ⊆ (𝐴 ∩ ℝ)) | 
| 34 | 7, 19, 33 | syl2an 289 | 
. . 3
⊢ ((1
∈ 𝐴 ∧
∀𝑦 ∈ 𝐴 (𝑦 + 1) ∈ 𝐴) → 𝑁 ⊆ (𝐴 ∩ ℝ)) | 
| 35 | 34, 8 | sstrdi 3195 | 
. 2
⊢ ((1
∈ 𝐴 ∧
∀𝑦 ∈ 𝐴 (𝑦 + 1) ∈ 𝐴) → 𝑁 ⊆ 𝐴) | 
| 36 | 3, 35 | sylan2br 288 | 
1
⊢ ((1
∈ 𝐴 ∧
∀𝑧 ∈ 𝐴 (𝑧 + 1) ∈ 𝐴) → 𝑁 ⊆ 𝐴) |