Proof of Theorem indpi
| Step | Hyp | Ref
| Expression |
| 1 | | 1oex 8490 |
. . . . . 6
⊢
1o ∈ V |
| 2 | 1 | eqvinc 3628 |
. . . . 5
⊢
(1o = 𝐴
↔ ∃𝑥(𝑥 = 1o ∧ 𝑥 = 𝐴)) |
| 3 | | indpi.4 |
. . . . 5
⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜏)) |
| 4 | | indpi.5 |
. . . . . 6
⊢ 𝜓 |
| 5 | | indpi.1 |
. . . . . 6
⊢ (𝑥 = 1o → (𝜑 ↔ 𝜓)) |
| 6 | 4, 5 | mpbiri 258 |
. . . . 5
⊢ (𝑥 = 1o → 𝜑) |
| 7 | 2, 3, 6 | gencl 3502 |
. . . 4
⊢
(1o = 𝐴
→ 𝜏) |
| 8 | 7 | eqcoms 2743 |
. . 3
⊢ (𝐴 = 1o → 𝜏) |
| 9 | 8 | a1i 11 |
. 2
⊢ (𝐴 ∈ N →
(𝐴 = 1o →
𝜏)) |
| 10 | | pinn 10892 |
. . . . 5
⊢ (𝐴 ∈ N →
𝐴 ∈
ω) |
| 11 | | elni2 10891 |
. . . . . 6
⊢ (𝐴 ∈ N ↔
(𝐴 ∈ ω ∧
∅ ∈ 𝐴)) |
| 12 | | nnord 7869 |
. . . . . . . . 9
⊢ (𝐴 ∈ ω → Ord 𝐴) |
| 13 | | ordsucss 7812 |
. . . . . . . . 9
⊢ (Ord
𝐴 → (∅ ∈
𝐴 → suc ∅
⊆ 𝐴)) |
| 14 | 12, 13 | syl 17 |
. . . . . . . 8
⊢ (𝐴 ∈ ω → (∅
∈ 𝐴 → suc ∅
⊆ 𝐴)) |
| 15 | | df-1o 8480 |
. . . . . . . . 9
⊢
1o = suc ∅ |
| 16 | 15 | sseq1i 3987 |
. . . . . . . 8
⊢
(1o ⊆ 𝐴 ↔ suc ∅ ⊆ 𝐴) |
| 17 | 14, 16 | imbitrrdi 252 |
. . . . . . 7
⊢ (𝐴 ∈ ω → (∅
∈ 𝐴 →
1o ⊆ 𝐴)) |
| 18 | 17 | imp 406 |
. . . . . 6
⊢ ((𝐴 ∈ ω ∧ ∅
∈ 𝐴) →
1o ⊆ 𝐴) |
| 19 | 11, 18 | sylbi 217 |
. . . . 5
⊢ (𝐴 ∈ N →
1o ⊆ 𝐴) |
| 20 | | 1onn 8652 |
. . . . . 6
⊢
1o ∈ ω |
| 21 | | eleq1 2822 |
. . . . . . . . 9
⊢ (𝑥 = 1o → (𝑥 ∈ N ↔
1o ∈ N)) |
| 22 | | breq2 5123 |
. . . . . . . . 9
⊢ (𝑥 = 1o →
(1o <N 𝑥 ↔ 1o
<N 1o)) |
| 23 | 21, 22 | anbi12d 632 |
. . . . . . . 8
⊢ (𝑥 = 1o → ((𝑥 ∈ N ∧
1o <N 𝑥) ↔ (1o ∈
N ∧ 1o <N
1o))) |
| 24 | 23, 5 | imbi12d 344 |
. . . . . . 7
⊢ (𝑥 = 1o → (((𝑥 ∈ N ∧
1o <N 𝑥) → 𝜑) ↔ ((1o ∈
N ∧ 1o <N
1o) → 𝜓))) |
| 25 | | eleq1 2822 |
. . . . . . . . 9
⊢ (𝑥 = 𝑦 → (𝑥 ∈ N ↔ 𝑦 ∈
N)) |
| 26 | | breq2 5123 |
. . . . . . . . 9
⊢ (𝑥 = 𝑦 → (1o
<N 𝑥 ↔ 1o
<N 𝑦)) |
| 27 | 25, 26 | anbi12d 632 |
. . . . . . . 8
⊢ (𝑥 = 𝑦 → ((𝑥 ∈ N ∧ 1o
<N 𝑥) ↔ (𝑦 ∈ N ∧ 1o
<N 𝑦))) |
| 28 | | indpi.2 |
. . . . . . . 8
⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜒)) |
| 29 | 27, 28 | imbi12d 344 |
. . . . . . 7
⊢ (𝑥 = 𝑦 → (((𝑥 ∈ N ∧ 1o
<N 𝑥) → 𝜑) ↔ ((𝑦 ∈ N ∧ 1o
<N 𝑦) → 𝜒))) |
| 30 | | pinn 10892 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 ∈ N →
𝑥 ∈
ω) |
| 31 | | eleq1 2822 |
. . . . . . . . . . . . . . . 16
⊢ (𝑥 = suc 𝑦 → (𝑥 ∈ ω ↔ suc 𝑦 ∈ ω)) |
| 32 | | peano2b 7878 |
. . . . . . . . . . . . . . . 16
⊢ (𝑦 ∈ ω ↔ suc 𝑦 ∈
ω) |
| 33 | 31, 32 | bitr4di 289 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 = suc 𝑦 → (𝑥 ∈ ω ↔ 𝑦 ∈ ω)) |
| 34 | 30, 33 | imbitrid 244 |
. . . . . . . . . . . . . 14
⊢ (𝑥 = suc 𝑦 → (𝑥 ∈ N → 𝑦 ∈
ω)) |
| 35 | 34 | adantrd 491 |
. . . . . . . . . . . . 13
⊢ (𝑥 = suc 𝑦 → ((𝑥 ∈ N ∧ 1o
<N 𝑥) → 𝑦 ∈ ω)) |
| 36 | | 1pi 10897 |
. . . . . . . . . . . . . . . 16
⊢
1o ∈ N |
| 37 | | ltpiord 10901 |
. . . . . . . . . . . . . . . 16
⊢
((1o ∈ N ∧ 𝑥 ∈ N) →
(1o <N 𝑥 ↔ 1o ∈ 𝑥)) |
| 38 | 36, 37 | mpan 690 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 ∈ N →
(1o <N 𝑥 ↔ 1o ∈ 𝑥)) |
| 39 | 38 | biimpa 476 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 ∈ N ∧
1o <N 𝑥) → 1o ∈ 𝑥) |
| 40 | | eleq2 2823 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 = suc 𝑦 → (1o ∈ 𝑥 ↔ 1o ∈ suc
𝑦)) |
| 41 | | elsuci 6421 |
. . . . . . . . . . . . . . . 16
⊢
(1o ∈ suc 𝑦 → (1o ∈ 𝑦 ∨ 1o = 𝑦)) |
| 42 | | ne0i 4316 |
. . . . . . . . . . . . . . . . 17
⊢
(1o ∈ 𝑦 → 𝑦 ≠ ∅) |
| 43 | | 0lt1o 8516 |
. . . . . . . . . . . . . . . . . . 19
⊢ ∅
∈ 1o |
| 44 | | eleq2 2823 |
. . . . . . . . . . . . . . . . . . 19
⊢
(1o = 𝑦
→ (∅ ∈ 1o ↔ ∅ ∈ 𝑦)) |
| 45 | 43, 44 | mpbii 233 |
. . . . . . . . . . . . . . . . . 18
⊢
(1o = 𝑦
→ ∅ ∈ 𝑦) |
| 46 | 45 | ne0d 4317 |
. . . . . . . . . . . . . . . . 17
⊢
(1o = 𝑦
→ 𝑦 ≠
∅) |
| 47 | 42, 46 | jaoi 857 |
. . . . . . . . . . . . . . . 16
⊢
((1o ∈ 𝑦 ∨ 1o = 𝑦) → 𝑦 ≠ ∅) |
| 48 | 41, 47 | syl 17 |
. . . . . . . . . . . . . . 15
⊢
(1o ∈ suc 𝑦 → 𝑦 ≠ ∅) |
| 49 | 40, 48 | biimtrdi 253 |
. . . . . . . . . . . . . 14
⊢ (𝑥 = suc 𝑦 → (1o ∈ 𝑥 → 𝑦 ≠ ∅)) |
| 50 | 39, 49 | syl5 34 |
. . . . . . . . . . . . 13
⊢ (𝑥 = suc 𝑦 → ((𝑥 ∈ N ∧ 1o
<N 𝑥) → 𝑦 ≠ ∅)) |
| 51 | 35, 50 | jcad 512 |
. . . . . . . . . . . 12
⊢ (𝑥 = suc 𝑦 → ((𝑥 ∈ N ∧ 1o
<N 𝑥) → (𝑦 ∈ ω ∧ 𝑦 ≠ ∅))) |
| 52 | | elni 10890 |
. . . . . . . . . . . 12
⊢ (𝑦 ∈ N ↔
(𝑦 ∈ ω ∧
𝑦 ≠
∅)) |
| 53 | 51, 52 | imbitrrdi 252 |
. . . . . . . . . . 11
⊢ (𝑥 = suc 𝑦 → ((𝑥 ∈ N ∧ 1o
<N 𝑥) → 𝑦 ∈ N)) |
| 54 | | simpr 484 |
. . . . . . . . . . . 12
⊢ ((𝑥 ∈ N ∧
1o <N 𝑥) → 1o
<N 𝑥) |
| 55 | | breq2 5123 |
. . . . . . . . . . . 12
⊢ (𝑥 = suc 𝑦 → (1o
<N 𝑥 ↔ 1o
<N suc 𝑦)) |
| 56 | 54, 55 | imbitrid 244 |
. . . . . . . . . . 11
⊢ (𝑥 = suc 𝑦 → ((𝑥 ∈ N ∧ 1o
<N 𝑥) → 1o
<N suc 𝑦)) |
| 57 | 53, 56 | jcad 512 |
. . . . . . . . . 10
⊢ (𝑥 = suc 𝑦 → ((𝑥 ∈ N ∧ 1o
<N 𝑥) → (𝑦 ∈ N ∧ 1o
<N suc 𝑦))) |
| 58 | | addclpi 10906 |
. . . . . . . . . . . . . . 15
⊢ ((𝑦 ∈ N ∧
1o ∈ N) → (𝑦 +N 1o)
∈ N) |
| 59 | 36, 58 | mpan2 691 |
. . . . . . . . . . . . . 14
⊢ (𝑦 ∈ N →
(𝑦
+N 1o) ∈
N) |
| 60 | | addpiord 10898 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((𝑦 ∈ N ∧
1o ∈ N) → (𝑦 +N 1o) =
(𝑦 +o
1o)) |
| 61 | 36, 60 | mpan2 691 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑦 ∈ N →
(𝑦
+N 1o) = (𝑦 +o
1o)) |
| 62 | | pion 10893 |
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑦 ∈ N →
𝑦 ∈
On) |
| 63 | | oa1suc 8543 |
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑦 ∈ On → (𝑦 +o 1o) =
suc 𝑦) |
| 64 | 62, 63 | syl 17 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑦 ∈ N →
(𝑦 +o
1o) = suc 𝑦) |
| 65 | 61, 64 | eqtrd 2770 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑦 ∈ N →
(𝑦
+N 1o) = suc 𝑦) |
| 66 | 65 | eqeq2d 2746 |
. . . . . . . . . . . . . . . 16
⊢ (𝑦 ∈ N →
(𝑥 = (𝑦 +N 1o)
↔ 𝑥 = suc 𝑦)) |
| 67 | 66 | biimparc 479 |
. . . . . . . . . . . . . . 15
⊢ ((𝑥 = suc 𝑦 ∧ 𝑦 ∈ N) → 𝑥 = (𝑦 +N
1o)) |
| 68 | 67 | eleq1d 2819 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 = suc 𝑦 ∧ 𝑦 ∈ N) → (𝑥 ∈ N ↔
(𝑦
+N 1o) ∈
N)) |
| 69 | 59, 68 | imbitrrid 246 |
. . . . . . . . . . . . 13
⊢ ((𝑥 = suc 𝑦 ∧ 𝑦 ∈ N) → (𝑦 ∈ N →
𝑥 ∈
N)) |
| 70 | 69 | ex 412 |
. . . . . . . . . . . 12
⊢ (𝑥 = suc 𝑦 → (𝑦 ∈ N → (𝑦 ∈ N →
𝑥 ∈
N))) |
| 71 | 70 | pm2.43d 53 |
. . . . . . . . . . 11
⊢ (𝑥 = suc 𝑦 → (𝑦 ∈ N → 𝑥 ∈
N)) |
| 72 | 55 | biimprd 248 |
. . . . . . . . . . 11
⊢ (𝑥 = suc 𝑦 → (1o
<N suc 𝑦 → 1o
<N 𝑥)) |
| 73 | 71, 72 | anim12d 609 |
. . . . . . . . . 10
⊢ (𝑥 = suc 𝑦 → ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → (𝑥 ∈ N ∧ 1o
<N 𝑥))) |
| 74 | 57, 73 | impbid 212 |
. . . . . . . . 9
⊢ (𝑥 = suc 𝑦 → ((𝑥 ∈ N ∧ 1o
<N 𝑥) ↔ (𝑦 ∈ N ∧ 1o
<N suc 𝑦))) |
| 75 | 74 | imbi1d 341 |
. . . . . . . 8
⊢ (𝑥 = suc 𝑦 → (((𝑥 ∈ N ∧ 1o
<N 𝑥) → 𝜑) ↔ ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜑))) |
| 76 | | indpi.3 |
. . . . . . . . . . . 12
⊢ (𝑥 = (𝑦 +N 1o)
→ (𝜑 ↔ 𝜃)) |
| 77 | 66, 76 | biimtrrdi 254 |
. . . . . . . . . . 11
⊢ (𝑦 ∈ N →
(𝑥 = suc 𝑦 → (𝜑 ↔ 𝜃))) |
| 78 | 77 | adantr 480 |
. . . . . . . . . 10
⊢ ((𝑦 ∈ N ∧
1o <N suc 𝑦) → (𝑥 = suc 𝑦 → (𝜑 ↔ 𝜃))) |
| 79 | 78 | com12 32 |
. . . . . . . . 9
⊢ (𝑥 = suc 𝑦 → ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → (𝜑 ↔ 𝜃))) |
| 80 | 79 | pm5.74d 273 |
. . . . . . . 8
⊢ (𝑥 = suc 𝑦 → (((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜑) ↔ ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜃))) |
| 81 | 75, 80 | bitrd 279 |
. . . . . . 7
⊢ (𝑥 = suc 𝑦 → (((𝑥 ∈ N ∧ 1o
<N 𝑥) → 𝜑) ↔ ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜃))) |
| 82 | | eleq1 2822 |
. . . . . . . . 9
⊢ (𝑥 = 𝐴 → (𝑥 ∈ N ↔ 𝐴 ∈
N)) |
| 83 | | breq2 5123 |
. . . . . . . . 9
⊢ (𝑥 = 𝐴 → (1o
<N 𝑥 ↔ 1o
<N 𝐴)) |
| 84 | 82, 83 | anbi12d 632 |
. . . . . . . 8
⊢ (𝑥 = 𝐴 → ((𝑥 ∈ N ∧ 1o
<N 𝑥) ↔ (𝐴 ∈ N ∧ 1o
<N 𝐴))) |
| 85 | 84, 3 | imbi12d 344 |
. . . . . . 7
⊢ (𝑥 = 𝐴 → (((𝑥 ∈ N ∧ 1o
<N 𝑥) → 𝜑) ↔ ((𝐴 ∈ N ∧ 1o
<N 𝐴) → 𝜏))) |
| 86 | 4 | 2a1i 12 |
. . . . . . 7
⊢
(1o ∈ ω → ((1o ∈
N ∧ 1o <N
1o) → 𝜓)) |
| 87 | | ltpiord 10901 |
. . . . . . . . . . . . . . 15
⊢
((1o ∈ N ∧ 𝑦 ∈ N) →
(1o <N 𝑦 ↔ 1o ∈ 𝑦)) |
| 88 | 36, 87 | mpan 690 |
. . . . . . . . . . . . . 14
⊢ (𝑦 ∈ N →
(1o <N 𝑦 ↔ 1o ∈ 𝑦)) |
| 89 | 88 | pm5.32i 574 |
. . . . . . . . . . . . 13
⊢ ((𝑦 ∈ N ∧
1o <N 𝑦) ↔ (𝑦 ∈ N ∧ 1o
∈ 𝑦)) |
| 90 | 89 | simplbi2 500 |
. . . . . . . . . . . 12
⊢ (𝑦 ∈ N →
(1o ∈ 𝑦
→ (𝑦 ∈
N ∧ 1o <N 𝑦))) |
| 91 | 90 | imim1d 82 |
. . . . . . . . . . 11
⊢ (𝑦 ∈ N →
(((𝑦 ∈ N
∧ 1o <N 𝑦) → 𝜒) → (1o ∈ 𝑦 → 𝜒))) |
| 92 | | ltrelpi 10903 |
. . . . . . . . . . . . . . 15
⊢
<N ⊆ (N ×
N) |
| 93 | 92 | brel 5719 |
. . . . . . . . . . . . . 14
⊢
(1o <N suc 𝑦 → (1o ∈ N
∧ suc 𝑦 ∈
N)) |
| 94 | | ltpiord 10901 |
. . . . . . . . . . . . . 14
⊢
((1o ∈ N ∧ suc 𝑦 ∈ N) →
(1o <N suc 𝑦 ↔ 1o ∈ suc 𝑦)) |
| 95 | 93, 94 | syl 17 |
. . . . . . . . . . . . 13
⊢
(1o <N suc 𝑦 → (1o
<N suc 𝑦 ↔ 1o ∈ suc 𝑦)) |
| 96 | 95 | ibi 267 |
. . . . . . . . . . . 12
⊢
(1o <N suc 𝑦 → 1o ∈ suc 𝑦) |
| 97 | 1 | eqvinc 3628 |
. . . . . . . . . . . . . . 15
⊢
(1o = 𝑦
↔ ∃𝑥(𝑥 = 1o ∧ 𝑥 = 𝑦)) |
| 98 | 97, 28, 6 | gencl 3502 |
. . . . . . . . . . . . . 14
⊢
(1o = 𝑦
→ 𝜒) |
| 99 | | jao 962 |
. . . . . . . . . . . . . 14
⊢
((1o ∈ 𝑦 → 𝜒) → ((1o = 𝑦 → 𝜒) → ((1o ∈ 𝑦 ∨ 1o = 𝑦) → 𝜒))) |
| 100 | 98, 99 | mpi 20 |
. . . . . . . . . . . . 13
⊢
((1o ∈ 𝑦 → 𝜒) → ((1o ∈ 𝑦 ∨ 1o = 𝑦) → 𝜒)) |
| 101 | 41, 100 | syl5 34 |
. . . . . . . . . . . 12
⊢
((1o ∈ 𝑦 → 𝜒) → (1o ∈ suc 𝑦 → 𝜒)) |
| 102 | 96, 101 | syl5 34 |
. . . . . . . . . . 11
⊢
((1o ∈ 𝑦 → 𝜒) → (1o
<N suc 𝑦 → 𝜒)) |
| 103 | 91, 102 | syl6com 37 |
. . . . . . . . . 10
⊢ (((𝑦 ∈ N ∧
1o <N 𝑦) → 𝜒) → (𝑦 ∈ N → (1o
<N suc 𝑦 → 𝜒))) |
| 104 | 103 | impd 410 |
. . . . . . . . 9
⊢ (((𝑦 ∈ N ∧
1o <N 𝑦) → 𝜒) → ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜒)) |
| 105 | 15 | sseq1i 3987 |
. . . . . . . . . . 11
⊢
(1o ⊆ 𝑦 ↔ suc ∅ ⊆ 𝑦) |
| 106 | | 0ex 5277 |
. . . . . . . . . . . 12
⊢ ∅
∈ V |
| 107 | | sucssel 6449 |
. . . . . . . . . . . 12
⊢ (∅
∈ V → (suc ∅ ⊆ 𝑦 → ∅ ∈ 𝑦)) |
| 108 | 106, 107 | ax-mp 5 |
. . . . . . . . . . 11
⊢ (suc
∅ ⊆ 𝑦 →
∅ ∈ 𝑦) |
| 109 | 105, 108 | sylbi 217 |
. . . . . . . . . 10
⊢
(1o ⊆ 𝑦 → ∅ ∈ 𝑦) |
| 110 | | elni2 10891 |
. . . . . . . . . . 11
⊢ (𝑦 ∈ N ↔
(𝑦 ∈ ω ∧
∅ ∈ 𝑦)) |
| 111 | | indpi.6 |
. . . . . . . . . . 11
⊢ (𝑦 ∈ N →
(𝜒 → 𝜃)) |
| 112 | 110, 111 | sylbir 235 |
. . . . . . . . . 10
⊢ ((𝑦 ∈ ω ∧ ∅
∈ 𝑦) → (𝜒 → 𝜃)) |
| 113 | 109, 112 | sylan2 593 |
. . . . . . . . 9
⊢ ((𝑦 ∈ ω ∧
1o ⊆ 𝑦)
→ (𝜒 → 𝜃)) |
| 114 | 104, 113 | syl9r 78 |
. . . . . . . 8
⊢ ((𝑦 ∈ ω ∧
1o ⊆ 𝑦)
→ (((𝑦 ∈
N ∧ 1o <N 𝑦) → 𝜒) → ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜃))) |
| 115 | 114 | adantlr 715 |
. . . . . . 7
⊢ (((𝑦 ∈ ω ∧
1o ∈ ω) ∧ 1o ⊆ 𝑦) → (((𝑦 ∈ N ∧ 1o
<N 𝑦) → 𝜒) → ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜃))) |
| 116 | 24, 29, 81, 85, 86, 115 | findsg 7893 |
. . . . . 6
⊢ (((𝐴 ∈ ω ∧
1o ∈ ω) ∧ 1o ⊆ 𝐴) → ((𝐴 ∈ N ∧ 1o
<N 𝐴) → 𝜏)) |
| 117 | 20, 116 | mpanl2 701 |
. . . . 5
⊢ ((𝐴 ∈ ω ∧
1o ⊆ 𝐴)
→ ((𝐴 ∈
N ∧ 1o <N 𝐴) → 𝜏)) |
| 118 | 10, 19, 117 | syl2anc 584 |
. . . 4
⊢ (𝐴 ∈ N →
((𝐴 ∈ N
∧ 1o <N 𝐴) → 𝜏)) |
| 119 | 118 | expd 415 |
. . 3
⊢ (𝐴 ∈ N →
(𝐴 ∈ N
→ (1o <N 𝐴 → 𝜏))) |
| 120 | 119 | pm2.43i 52 |
. 2
⊢ (𝐴 ∈ N →
(1o <N 𝐴 → 𝜏)) |
| 121 | | nlt1pi 10920 |
. . . 4
⊢ ¬
𝐴
<N 1o |
| 122 | | ltsopi 10902 |
. . . . . 6
⊢
<N Or N |
| 123 | | sotric 5591 |
. . . . . 6
⊢ ((
<N Or N ∧ (𝐴 ∈ N ∧ 1o
∈ N)) → (𝐴 <N
1o ↔ ¬ (𝐴 = 1o ∨ 1o
<N 𝐴))) |
| 124 | 122, 123 | mpan 690 |
. . . . 5
⊢ ((𝐴 ∈ N ∧
1o ∈ N) → (𝐴 <N
1o ↔ ¬ (𝐴 = 1o ∨ 1o
<N 𝐴))) |
| 125 | 36, 124 | mpan2 691 |
. . . 4
⊢ (𝐴 ∈ N →
(𝐴
<N 1o ↔ ¬ (𝐴 = 1o ∨ 1o
<N 𝐴))) |
| 126 | 121, 125 | mtbii 326 |
. . 3
⊢ (𝐴 ∈ N →
¬ ¬ (𝐴 =
1o ∨ 1o <N 𝐴)) |
| 127 | 126 | notnotrd 133 |
. 2
⊢ (𝐴 ∈ N →
(𝐴 = 1o ∨
1o <N 𝐴)) |
| 128 | 9, 120, 127 | mpjaod 860 |
1
⊢ (𝐴 ∈ N →
𝜏) |