Proof of Theorem indpi
Step | Hyp | Ref
| Expression |
1 | | 1oex 8280 |
. . . . . 6
⊢
1o ∈ V |
2 | 1 | eqvinc 3571 |
. . . . 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 257 |
. . . . 5
⊢ (𝑥 = 1o → 𝜑) |
7 | 2, 3, 6 | gencl 3461 |
. . . 4
⊢
(1o = 𝐴
→ 𝜏) |
8 | 7 | eqcoms 2746 |
. . 3
⊢ (𝐴 = 1o → 𝜏) |
9 | 8 | a1i 11 |
. 2
⊢ (𝐴 ∈ N →
(𝐴 = 1o →
𝜏)) |
10 | | pinn 10565 |
. . . . 5
⊢ (𝐴 ∈ N →
𝐴 ∈
ω) |
11 | | elni2 10564 |
. . . . . 6
⊢ (𝐴 ∈ N ↔
(𝐴 ∈ ω ∧
∅ ∈ 𝐴)) |
12 | | nnord 7695 |
. . . . . . . . 9
⊢ (𝐴 ∈ ω → Ord 𝐴) |
13 | | ordsucss 7640 |
. . . . . . . . 9
⊢ (Ord
𝐴 → (∅ ∈
𝐴 → suc ∅
⊆ 𝐴)) |
14 | 12, 13 | syl 17 |
. . . . . . . 8
⊢ (𝐴 ∈ ω → (∅
∈ 𝐴 → suc ∅
⊆ 𝐴)) |
15 | | df-1o 8267 |
. . . . . . . . 9
⊢
1o = suc ∅ |
16 | 15 | sseq1i 3945 |
. . . . . . . 8
⊢
(1o ⊆ 𝐴 ↔ suc ∅ ⊆ 𝐴) |
17 | 14, 16 | syl6ibr 251 |
. . . . . . 7
⊢ (𝐴 ∈ ω → (∅
∈ 𝐴 →
1o ⊆ 𝐴)) |
18 | 17 | imp 406 |
. . . . . 6
⊢ ((𝐴 ∈ ω ∧ ∅
∈ 𝐴) →
1o ⊆ 𝐴) |
19 | 11, 18 | sylbi 216 |
. . . . 5
⊢ (𝐴 ∈ N →
1o ⊆ 𝐴) |
20 | | 1onn 8432 |
. . . . . 6
⊢
1o ∈ ω |
21 | | eleq1 2826 |
. . . . . . . . 9
⊢ (𝑥 = 1o → (𝑥 ∈ N ↔
1o ∈ N)) |
22 | | breq2 5074 |
. . . . . . . . 9
⊢ (𝑥 = 1o →
(1o <N 𝑥 ↔ 1o
<N 1o)) |
23 | 21, 22 | anbi12d 630 |
. . . . . . . 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 2826 |
. . . . . . . . 9
⊢ (𝑥 = 𝑦 → (𝑥 ∈ N ↔ 𝑦 ∈
N)) |
26 | | breq2 5074 |
. . . . . . . . 9
⊢ (𝑥 = 𝑦 → (1o
<N 𝑥 ↔ 1o
<N 𝑦)) |
27 | 25, 26 | anbi12d 630 |
. . . . . . . 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 10565 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 ∈ N →
𝑥 ∈
ω) |
31 | | eleq1 2826 |
. . . . . . . . . . . . . . . 16
⊢ (𝑥 = suc 𝑦 → (𝑥 ∈ ω ↔ suc 𝑦 ∈ ω)) |
32 | | peano2b 7704 |
. . . . . . . . . . . . . . . 16
⊢ (𝑦 ∈ ω ↔ suc 𝑦 ∈
ω) |
33 | 31, 32 | bitr4di 288 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 = suc 𝑦 → (𝑥 ∈ ω ↔ 𝑦 ∈ ω)) |
34 | 30, 33 | syl5ib 243 |
. . . . . . . . . . . . . 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 10570 |
. . . . . . . . . . . . . . . 16
⊢
1o ∈ N |
37 | | ltpiord 10574 |
. . . . . . . . . . . . . . . 16
⊢
((1o ∈ N ∧ 𝑥 ∈ N) →
(1o <N 𝑥 ↔ 1o ∈ 𝑥)) |
38 | 36, 37 | mpan 686 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 ∈ N →
(1o <N 𝑥 ↔ 1o ∈ 𝑥)) |
39 | 38 | biimpa 476 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 ∈ N ∧
1o <N 𝑥) → 1o ∈ 𝑥) |
40 | | eleq2 2827 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 = suc 𝑦 → (1o ∈ 𝑥 ↔ 1o ∈ suc
𝑦)) |
41 | | elsuci 6317 |
. . . . . . . . . . . . . . . 16
⊢
(1o ∈ suc 𝑦 → (1o ∈ 𝑦 ∨ 1o = 𝑦)) |
42 | | ne0i 4265 |
. . . . . . . . . . . . . . . . 17
⊢
(1o ∈ 𝑦 → 𝑦 ≠ ∅) |
43 | | 0lt1o 8296 |
. . . . . . . . . . . . . . . . . . 19
⊢ ∅
∈ 1o |
44 | | eleq2 2827 |
. . . . . . . . . . . . . . . . . . 19
⊢
(1o = 𝑦
→ (∅ ∈ 1o ↔ ∅ ∈ 𝑦)) |
45 | 43, 44 | mpbii 232 |
. . . . . . . . . . . . . . . . . 18
⊢
(1o = 𝑦
→ ∅ ∈ 𝑦) |
46 | 45 | ne0d 4266 |
. . . . . . . . . . . . . . . . 17
⊢
(1o = 𝑦
→ 𝑦 ≠
∅) |
47 | 42, 46 | jaoi 853 |
. . . . . . . . . . . . . . . 16
⊢
((1o ∈ 𝑦 ∨ 1o = 𝑦) → 𝑦 ≠ ∅) |
48 | 41, 47 | syl 17 |
. . . . . . . . . . . . . . 15
⊢
(1o ∈ suc 𝑦 → 𝑦 ≠ ∅) |
49 | 40, 48 | syl6bi 252 |
. . . . . . . . . . . . . 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 10563 |
. . . . . . . . . . . 12
⊢ (𝑦 ∈ N ↔
(𝑦 ∈ ω ∧
𝑦 ≠
∅)) |
53 | 51, 52 | syl6ibr 251 |
. . . . . . . . . . 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 5074 |
. . . . . . . . . . . 12
⊢ (𝑥 = suc 𝑦 → (1o
<N 𝑥 ↔ 1o
<N suc 𝑦)) |
56 | 54, 55 | syl5ib 243 |
. . . . . . . . . . 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 10579 |
. . . . . . . . . . . . . . 15
⊢ ((𝑦 ∈ N ∧
1o ∈ N) → (𝑦 +N 1o)
∈ N) |
59 | 36, 58 | mpan2 687 |
. . . . . . . . . . . . . 14
⊢ (𝑦 ∈ N →
(𝑦
+N 1o) ∈
N) |
60 | | addpiord 10571 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((𝑦 ∈ N ∧
1o ∈ N) → (𝑦 +N 1o) =
(𝑦 +o
1o)) |
61 | 36, 60 | mpan2 687 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑦 ∈ N →
(𝑦
+N 1o) = (𝑦 +o
1o)) |
62 | | pion 10566 |
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑦 ∈ N →
𝑦 ∈
On) |
63 | | oa1suc 8323 |
. . . . . . . . . . . . . . . . . . 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 2778 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑦 ∈ N →
(𝑦
+N 1o) = suc 𝑦) |
66 | 65 | eqeq2d 2749 |
. . . . . . . . . . . . . . . 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 2823 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 = suc 𝑦 ∧ 𝑦 ∈ N) → (𝑥 ∈ N ↔
(𝑦
+N 1o) ∈
N)) |
69 | 59, 68 | syl5ibr 245 |
. . . . . . . . . . . . 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 247 |
. . . . . . . . . . 11
⊢ (𝑥 = suc 𝑦 → (1o
<N suc 𝑦 → 1o
<N 𝑥)) |
73 | 71, 72 | anim12d 608 |
. . . . . . . . . 10
⊢ (𝑥 = suc 𝑦 → ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → (𝑥 ∈ N ∧ 1o
<N 𝑥))) |
74 | 57, 73 | impbid 211 |
. . . . . . . . 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 | syl6bir 253 |
. . . . . . . . . . 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 272 |
. . . . . . . 8
⊢ (𝑥 = suc 𝑦 → (((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜑) ↔ ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜃))) |
81 | 75, 80 | bitrd 278 |
. . . . . . 7
⊢ (𝑥 = suc 𝑦 → (((𝑥 ∈ N ∧ 1o
<N 𝑥) → 𝜑) ↔ ((𝑦 ∈ N ∧ 1o
<N suc 𝑦) → 𝜃))) |
82 | | eleq1 2826 |
. . . . . . . . 9
⊢ (𝑥 = 𝐴 → (𝑥 ∈ N ↔ 𝐴 ∈
N)) |
83 | | breq2 5074 |
. . . . . . . . 9
⊢ (𝑥 = 𝐴 → (1o
<N 𝑥 ↔ 1o
<N 𝐴)) |
84 | 82, 83 | anbi12d 630 |
. . . . . . . 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 10574 |
. . . . . . . . . . . . . . 15
⊢
((1o ∈ N ∧ 𝑦 ∈ N) →
(1o <N 𝑦 ↔ 1o ∈ 𝑦)) |
88 | 36, 87 | mpan 686 |
. . . . . . . . . . . . . 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 10576 |
. . . . . . . . . . . . . . 15
⊢
<N ⊆ (N ×
N) |
93 | 92 | brel 5643 |
. . . . . . . . . . . . . 14
⊢
(1o <N suc 𝑦 → (1o ∈ N
∧ suc 𝑦 ∈
N)) |
94 | | ltpiord 10574 |
. . . . . . . . . . . . . 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 266 |
. . . . . . . . . . . 12
⊢
(1o <N suc 𝑦 → 1o ∈ suc 𝑦) |
97 | 1 | eqvinc 3571 |
. . . . . . . . . . . . . . 15
⊢
(1o = 𝑦
↔ ∃𝑥(𝑥 = 1o ∧ 𝑥 = 𝑦)) |
98 | 97, 28, 6 | gencl 3461 |
. . . . . . . . . . . . . 14
⊢
(1o = 𝑦
→ 𝜒) |
99 | | jao 957 |
. . . . . . . . . . . . . 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 3945 |
. . . . . . . . . . 11
⊢
(1o ⊆ 𝑦 ↔ suc ∅ ⊆ 𝑦) |
106 | | 0ex 5226 |
. . . . . . . . . . . 12
⊢ ∅
∈ V |
107 | | sucssel 6343 |
. . . . . . . . . . . 12
⊢ (∅
∈ V → (suc ∅ ⊆ 𝑦 → ∅ ∈ 𝑦)) |
108 | 106, 107 | ax-mp 5 |
. . . . . . . . . . 11
⊢ (suc
∅ ⊆ 𝑦 →
∅ ∈ 𝑦) |
109 | 105, 108 | sylbi 216 |
. . . . . . . . . 10
⊢
(1o ⊆ 𝑦 → ∅ ∈ 𝑦) |
110 | | elni2 10564 |
. . . . . . . . . . 11
⊢ (𝑦 ∈ N ↔
(𝑦 ∈ ω ∧
∅ ∈ 𝑦)) |
111 | | indpi.6 |
. . . . . . . . . . 11
⊢ (𝑦 ∈ N →
(𝜒 → 𝜃)) |
112 | 110, 111 | sylbir 234 |
. . . . . . . . . 10
⊢ ((𝑦 ∈ ω ∧ ∅
∈ 𝑦) → (𝜒 → 𝜃)) |
113 | 109, 112 | sylan2 592 |
. . . . . . . . 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 711 |
. . . . . . 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 7720 |
. . . . . 6
⊢ (((𝐴 ∈ ω ∧
1o ∈ ω) ∧ 1o ⊆ 𝐴) → ((𝐴 ∈ N ∧ 1o
<N 𝐴) → 𝜏)) |
117 | 20, 116 | mpanl2 697 |
. . . . 5
⊢ ((𝐴 ∈ ω ∧
1o ⊆ 𝐴)
→ ((𝐴 ∈
N ∧ 1o <N 𝐴) → 𝜏)) |
118 | 10, 19, 117 | syl2anc 583 |
. . . 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 10593 |
. . . 4
⊢ ¬
𝐴
<N 1o |
122 | | ltsopi 10575 |
. . . . . 6
⊢
<N Or N |
123 | | sotric 5522 |
. . . . . 6
⊢ ((
<N Or N ∧ (𝐴 ∈ N ∧ 1o
∈ N)) → (𝐴 <N
1o ↔ ¬ (𝐴 = 1o ∨ 1o
<N 𝐴))) |
124 | 122, 123 | mpan 686 |
. . . . 5
⊢ ((𝐴 ∈ N ∧
1o ∈ N) → (𝐴 <N
1o ↔ ¬ (𝐴 = 1o ∨ 1o
<N 𝐴))) |
125 | 36, 124 | mpan2 687 |
. . . 4
⊢ (𝐴 ∈ N →
(𝐴
<N 1o ↔ ¬ (𝐴 = 1o ∨ 1o
<N 𝐴))) |
126 | 121, 125 | mtbii 325 |
. . 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 856 |
1
⊢ (𝐴 ∈ N →
𝜏) |