Proof of Theorem cnfcom3lem
Step | Hyp | Ref
| Expression |
1 | | cnfcom.w |
. . 3
⊢ 𝑊 = (𝐺‘∪ dom
𝐺) |
2 | | cnfcom.a |
. . . 4
⊢ (𝜑 → 𝐴 ∈ On) |
3 | | suppssdm 7993 |
. . . . . 6
⊢ (𝐹 supp ∅) ⊆ dom 𝐹 |
4 | | cnfcom.f |
. . . . . . . . 9
⊢ 𝐹 = (◡(ω CNF 𝐴)‘𝐵) |
5 | | cnfcom.s |
. . . . . . . . . . . 12
⊢ 𝑆 = dom (ω CNF 𝐴) |
6 | | omelon 9404 |
. . . . . . . . . . . . 13
⊢ ω
∈ On |
7 | 6 | a1i 11 |
. . . . . . . . . . . 12
⊢ (𝜑 → ω ∈
On) |
8 | 5, 7, 2 | cantnff1o 9454 |
. . . . . . . . . . 11
⊢ (𝜑 → (ω CNF 𝐴):𝑆–1-1-onto→(ω ↑o 𝐴)) |
9 | | f1ocnv 6728 |
. . . . . . . . . . 11
⊢ ((ω
CNF 𝐴):𝑆–1-1-onto→(ω ↑o 𝐴) → ◡(ω CNF 𝐴):(ω ↑o 𝐴)–1-1-onto→𝑆) |
10 | | f1of 6716 |
. . . . . . . . . . 11
⊢ (◡(ω CNF 𝐴):(ω ↑o 𝐴)–1-1-onto→𝑆 → ◡(ω CNF 𝐴):(ω ↑o 𝐴)⟶𝑆) |
11 | 8, 9, 10 | 3syl 18 |
. . . . . . . . . 10
⊢ (𝜑 → ◡(ω CNF 𝐴):(ω ↑o 𝐴)⟶𝑆) |
12 | | cnfcom.b |
. . . . . . . . . 10
⊢ (𝜑 → 𝐵 ∈ (ω ↑o 𝐴)) |
13 | 11, 12 | ffvelrnd 6962 |
. . . . . . . . 9
⊢ (𝜑 → (◡(ω CNF 𝐴)‘𝐵) ∈ 𝑆) |
14 | 4, 13 | eqeltrid 2843 |
. . . . . . . 8
⊢ (𝜑 → 𝐹 ∈ 𝑆) |
15 | 5, 7, 2 | cantnfs 9424 |
. . . . . . . 8
⊢ (𝜑 → (𝐹 ∈ 𝑆 ↔ (𝐹:𝐴⟶ω ∧ 𝐹 finSupp ∅))) |
16 | 14, 15 | mpbid 231 |
. . . . . . 7
⊢ (𝜑 → (𝐹:𝐴⟶ω ∧ 𝐹 finSupp ∅)) |
17 | 16 | simpld 495 |
. . . . . 6
⊢ (𝜑 → 𝐹:𝐴⟶ω) |
18 | 3, 17 | fssdm 6620 |
. . . . 5
⊢ (𝜑 → (𝐹 supp ∅) ⊆ 𝐴) |
19 | | ovex 7308 |
. . . . . . . . . . 11
⊢ (𝐹 supp ∅) ∈
V |
20 | | cnfcom.g |
. . . . . . . . . . . 12
⊢ 𝐺 = OrdIso( E , (𝐹 supp ∅)) |
21 | 20 | oion 9295 |
. . . . . . . . . . 11
⊢ ((𝐹 supp ∅) ∈ V →
dom 𝐺 ∈
On) |
22 | 19, 21 | ax-mp 5 |
. . . . . . . . . 10
⊢ dom 𝐺 ∈ On |
23 | 22 | elexi 3451 |
. . . . . . . . 9
⊢ dom 𝐺 ∈ V |
24 | 23 | uniex 7594 |
. . . . . . . 8
⊢ ∪ dom 𝐺 ∈ V |
25 | 24 | sucid 6345 |
. . . . . . 7
⊢ ∪ dom 𝐺 ∈ suc ∪ dom
𝐺 |
26 | | cnfcom.h |
. . . . . . . 8
⊢ 𝐻 = seqω((𝑘 ∈ V, 𝑧 ∈ V ↦ (𝑀 +o 𝑧)), ∅) |
27 | | cnfcom.t |
. . . . . . . 8
⊢ 𝑇 = seqω((𝑘 ∈ V, 𝑓 ∈ V ↦ 𝐾), ∅) |
28 | | cnfcom.m |
. . . . . . . 8
⊢ 𝑀 = ((ω ↑o
(𝐺‘𝑘)) ·o (𝐹‘(𝐺‘𝑘))) |
29 | | cnfcom.k |
. . . . . . . 8
⊢ 𝐾 = ((𝑥 ∈ 𝑀 ↦ (dom 𝑓 +o 𝑥)) ∪ ◡(𝑥 ∈ dom 𝑓 ↦ (𝑀 +o 𝑥))) |
30 | | cnfcom3.1 |
. . . . . . . . 9
⊢ (𝜑 → ω ⊆ 𝐵) |
31 | | peano1 7735 |
. . . . . . . . . 10
⊢ ∅
∈ ω |
32 | 31 | a1i 11 |
. . . . . . . . 9
⊢ (𝜑 → ∅ ∈
ω) |
33 | 30, 32 | sseldd 3922 |
. . . . . . . 8
⊢ (𝜑 → ∅ ∈ 𝐵) |
34 | 5, 2, 12, 4, 20, 26, 27, 28, 29, 1, 33 | cnfcom2lem 9459 |
. . . . . . 7
⊢ (𝜑 → dom 𝐺 = suc ∪ dom
𝐺) |
35 | 25, 34 | eleqtrrid 2846 |
. . . . . 6
⊢ (𝜑 → ∪ dom 𝐺 ∈ dom 𝐺) |
36 | 20 | oif 9289 |
. . . . . . 7
⊢ 𝐺:dom 𝐺⟶(𝐹 supp ∅) |
37 | 36 | ffvelrni 6960 |
. . . . . 6
⊢ (∪ dom 𝐺 ∈ dom 𝐺 → (𝐺‘∪ dom
𝐺) ∈ (𝐹 supp ∅)) |
38 | 35, 37 | syl 17 |
. . . . 5
⊢ (𝜑 → (𝐺‘∪ dom
𝐺) ∈ (𝐹 supp ∅)) |
39 | 18, 38 | sseldd 3922 |
. . . 4
⊢ (𝜑 → (𝐺‘∪ dom
𝐺) ∈ 𝐴) |
40 | | onelon 6291 |
. . . 4
⊢ ((𝐴 ∈ On ∧ (𝐺‘∪ dom 𝐺) ∈ 𝐴) → (𝐺‘∪ dom
𝐺) ∈
On) |
41 | 2, 39, 40 | syl2anc 584 |
. . 3
⊢ (𝜑 → (𝐺‘∪ dom
𝐺) ∈
On) |
42 | 1, 41 | eqeltrid 2843 |
. 2
⊢ (𝜑 → 𝑊 ∈ On) |
43 | | oecl 8367 |
. . . . . . 7
⊢ ((ω
∈ On ∧ 𝐴 ∈
On) → (ω ↑o 𝐴) ∈ On) |
44 | 6, 2, 43 | sylancr 587 |
. . . . . 6
⊢ (𝜑 → (ω
↑o 𝐴)
∈ On) |
45 | | onelon 6291 |
. . . . . 6
⊢
(((ω ↑o 𝐴) ∈ On ∧ 𝐵 ∈ (ω ↑o 𝐴)) → 𝐵 ∈ On) |
46 | 44, 12, 45 | syl2anc 584 |
. . . . 5
⊢ (𝜑 → 𝐵 ∈ On) |
47 | | ontri1 6300 |
. . . . 5
⊢ ((ω
∈ On ∧ 𝐵 ∈
On) → (ω ⊆ 𝐵 ↔ ¬ 𝐵 ∈ ω)) |
48 | 6, 46, 47 | sylancr 587 |
. . . 4
⊢ (𝜑 → (ω ⊆ 𝐵 ↔ ¬ 𝐵 ∈ ω)) |
49 | 30, 48 | mpbid 231 |
. . 3
⊢ (𝜑 → ¬ 𝐵 ∈ ω) |
50 | 4 | fveq2i 6777 |
. . . . . . . 8
⊢ ((ω
CNF 𝐴)‘𝐹) = ((ω CNF 𝐴)‘(◡(ω CNF 𝐴)‘𝐵)) |
51 | | f1ocnvfv2 7149 |
. . . . . . . . 9
⊢
(((ω CNF 𝐴):𝑆–1-1-onto→(ω ↑o 𝐴) ∧ 𝐵 ∈ (ω ↑o 𝐴)) → ((ω CNF 𝐴)‘(◡(ω CNF 𝐴)‘𝐵)) = 𝐵) |
52 | 8, 12, 51 | syl2anc 584 |
. . . . . . . 8
⊢ (𝜑 → ((ω CNF 𝐴)‘(◡(ω CNF 𝐴)‘𝐵)) = 𝐵) |
53 | 50, 52 | eqtrid 2790 |
. . . . . . 7
⊢ (𝜑 → ((ω CNF 𝐴)‘𝐹) = 𝐵) |
54 | 53 | adantr 481 |
. . . . . 6
⊢ ((𝜑 ∧ 𝑊 = ∅) → ((ω CNF 𝐴)‘𝐹) = 𝐵) |
55 | 6 | a1i 11 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑊 = ∅) → ω ∈
On) |
56 | 2 | adantr 481 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑊 = ∅) → 𝐴 ∈ On) |
57 | 14 | adantr 481 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑊 = ∅) → 𝐹 ∈ 𝑆) |
58 | 31 | a1i 11 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑊 = ∅) → ∅ ∈
ω) |
59 | | 1on 8309 |
. . . . . . . . 9
⊢
1o ∈ On |
60 | 59 | a1i 11 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑊 = ∅) → 1o ∈
On) |
61 | | ovexd 7310 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝜑 → (𝐹 supp ∅) ∈ V) |
62 | 5, 7, 2, 20, 14 | cantnfcl 9425 |
. . . . . . . . . . . . . . . . . . . . 21
⊢ (𝜑 → ( E We (𝐹 supp ∅) ∧ dom 𝐺 ∈ ω)) |
63 | 62 | simpld 495 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝜑 → E We (𝐹 supp ∅)) |
64 | 20 | oiiso 9296 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (((𝐹 supp ∅) ∈ V ∧ E
We (𝐹 supp ∅)) →
𝐺 Isom E , E (dom 𝐺, (𝐹 supp ∅))) |
65 | 61, 63, 64 | syl2anc 584 |
. . . . . . . . . . . . . . . . . . 19
⊢ (𝜑 → 𝐺 Isom E , E (dom 𝐺, (𝐹 supp ∅))) |
66 | 65 | ad2antrr 723 |
. . . . . . . . . . . . . . . . . 18
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → 𝐺 Isom E , E (dom 𝐺, (𝐹 supp ∅))) |
67 | | isof1o 7194 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝐺 Isom E , E (dom 𝐺, (𝐹 supp ∅)) → 𝐺:dom 𝐺–1-1-onto→(𝐹 supp ∅)) |
68 | 66, 67 | syl 17 |
. . . . . . . . . . . . . . . . 17
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → 𝐺:dom 𝐺–1-1-onto→(𝐹 supp ∅)) |
69 | | f1ocnv 6728 |
. . . . . . . . . . . . . . . . 17
⊢ (𝐺:dom 𝐺–1-1-onto→(𝐹 supp ∅) → ◡𝐺:(𝐹 supp ∅)–1-1-onto→dom
𝐺) |
70 | | f1of 6716 |
. . . . . . . . . . . . . . . . 17
⊢ (◡𝐺:(𝐹 supp ∅)–1-1-onto→dom
𝐺 → ◡𝐺:(𝐹 supp ∅)⟶dom 𝐺) |
71 | 68, 69, 70 | 3syl 18 |
. . . . . . . . . . . . . . . 16
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → ◡𝐺:(𝐹 supp ∅)⟶dom 𝐺) |
72 | | ffvelrn 6959 |
. . . . . . . . . . . . . . . 16
⊢ ((◡𝐺:(𝐹 supp ∅)⟶dom 𝐺 ∧ 𝑥 ∈ (𝐹 supp ∅)) → (◡𝐺‘𝑥) ∈ dom 𝐺) |
73 | 71, 72 | sylancom 588 |
. . . . . . . . . . . . . . 15
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (◡𝐺‘𝑥) ∈ dom 𝐺) |
74 | | elssuni 4871 |
. . . . . . . . . . . . . . 15
⊢ ((◡𝐺‘𝑥) ∈ dom 𝐺 → (◡𝐺‘𝑥) ⊆ ∪ dom
𝐺) |
75 | 73, 74 | syl 17 |
. . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (◡𝐺‘𝑥) ⊆ ∪ dom
𝐺) |
76 | | onelon 6291 |
. . . . . . . . . . . . . . . 16
⊢ ((dom
𝐺 ∈ On ∧ (◡𝐺‘𝑥) ∈ dom 𝐺) → (◡𝐺‘𝑥) ∈ On) |
77 | 22, 73, 76 | sylancr 587 |
. . . . . . . . . . . . . . 15
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (◡𝐺‘𝑥) ∈ On) |
78 | | onuni 7638 |
. . . . . . . . . . . . . . . 16
⊢ (dom
𝐺 ∈ On → ∪ dom 𝐺 ∈ On) |
79 | 22, 78 | ax-mp 5 |
. . . . . . . . . . . . . . 15
⊢ ∪ dom 𝐺 ∈ On |
80 | | ontri1 6300 |
. . . . . . . . . . . . . . 15
⊢ (((◡𝐺‘𝑥) ∈ On ∧ ∪ dom 𝐺 ∈ On) → ((◡𝐺‘𝑥) ⊆ ∪ dom
𝐺 ↔ ¬ ∪ dom 𝐺 ∈ (◡𝐺‘𝑥))) |
81 | 77, 79, 80 | sylancl 586 |
. . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → ((◡𝐺‘𝑥) ⊆ ∪ dom
𝐺 ↔ ¬ ∪ dom 𝐺 ∈ (◡𝐺‘𝑥))) |
82 | 75, 81 | mpbid 231 |
. . . . . . . . . . . . 13
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → ¬ ∪ dom 𝐺 ∈ (◡𝐺‘𝑥)) |
83 | 35 | ad2antrr 723 |
. . . . . . . . . . . . . . . 16
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → ∪ dom 𝐺 ∈ dom 𝐺) |
84 | | isorel 7197 |
. . . . . . . . . . . . . . . 16
⊢ ((𝐺 Isom E , E (dom 𝐺, (𝐹 supp ∅)) ∧ (∪ dom 𝐺 ∈ dom 𝐺 ∧ (◡𝐺‘𝑥) ∈ dom 𝐺)) → (∪ dom
𝐺 E (◡𝐺‘𝑥) ↔ (𝐺‘∪ dom
𝐺) E (𝐺‘(◡𝐺‘𝑥)))) |
85 | 66, 83, 73, 84 | syl12anc 834 |
. . . . . . . . . . . . . . 15
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (∪ dom 𝐺 E (◡𝐺‘𝑥) ↔ (𝐺‘∪ dom
𝐺) E (𝐺‘(◡𝐺‘𝑥)))) |
86 | | fvex 6787 |
. . . . . . . . . . . . . . . 16
⊢ (◡𝐺‘𝑥) ∈ V |
87 | 86 | epeli 5497 |
. . . . . . . . . . . . . . 15
⊢ (∪ dom 𝐺 E (◡𝐺‘𝑥) ↔ ∪ dom
𝐺 ∈ (◡𝐺‘𝑥)) |
88 | 1 | breq1i 5081 |
. . . . . . . . . . . . . . . 16
⊢ (𝑊 E (𝐺‘(◡𝐺‘𝑥)) ↔ (𝐺‘∪ dom
𝐺) E (𝐺‘(◡𝐺‘𝑥))) |
89 | | fvex 6787 |
. . . . . . . . . . . . . . . . 17
⊢ (𝐺‘(◡𝐺‘𝑥)) ∈ V |
90 | 89 | epeli 5497 |
. . . . . . . . . . . . . . . 16
⊢ (𝑊 E (𝐺‘(◡𝐺‘𝑥)) ↔ 𝑊 ∈ (𝐺‘(◡𝐺‘𝑥))) |
91 | 88, 90 | bitr3i 276 |
. . . . . . . . . . . . . . 15
⊢ ((𝐺‘∪ dom 𝐺) E (𝐺‘(◡𝐺‘𝑥)) ↔ 𝑊 ∈ (𝐺‘(◡𝐺‘𝑥))) |
92 | 85, 87, 91 | 3bitr3g 313 |
. . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (∪ dom 𝐺 ∈ (◡𝐺‘𝑥) ↔ 𝑊 ∈ (𝐺‘(◡𝐺‘𝑥)))) |
93 | | simplr 766 |
. . . . . . . . . . . . . . 15
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → 𝑊 = ∅) |
94 | | f1ocnvfv2 7149 |
. . . . . . . . . . . . . . . 16
⊢ ((𝐺:dom 𝐺–1-1-onto→(𝐹 supp ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (𝐺‘(◡𝐺‘𝑥)) = 𝑥) |
95 | 68, 94 | sylancom 588 |
. . . . . . . . . . . . . . 15
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (𝐺‘(◡𝐺‘𝑥)) = 𝑥) |
96 | 93, 95 | eleq12d 2833 |
. . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (𝑊 ∈ (𝐺‘(◡𝐺‘𝑥)) ↔ ∅ ∈ 𝑥)) |
97 | 92, 96 | bitrd 278 |
. . . . . . . . . . . . 13
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (∪ dom 𝐺 ∈ (◡𝐺‘𝑥) ↔ ∅ ∈ 𝑥)) |
98 | 82, 97 | mtbid 324 |
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → ¬ ∅ ∈
𝑥) |
99 | | onss 7634 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝐴 ∈ On → 𝐴 ⊆ On) |
100 | 2, 99 | syl 17 |
. . . . . . . . . . . . . . . . 17
⊢ (𝜑 → 𝐴 ⊆ On) |
101 | 18, 100 | sstrd 3931 |
. . . . . . . . . . . . . . . 16
⊢ (𝜑 → (𝐹 supp ∅) ⊆ On) |
102 | 101 | adantr 481 |
. . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ 𝑊 = ∅) → (𝐹 supp ∅) ⊆ On) |
103 | 102 | sselda 3921 |
. . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → 𝑥 ∈ On) |
104 | | on0eqel 6384 |
. . . . . . . . . . . . . 14
⊢ (𝑥 ∈ On → (𝑥 = ∅ ∨ ∅ ∈
𝑥)) |
105 | 103, 104 | syl 17 |
. . . . . . . . . . . . 13
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (𝑥 = ∅ ∨ ∅ ∈ 𝑥)) |
106 | 105 | ord 861 |
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → (¬ 𝑥 = ∅ → ∅ ∈
𝑥)) |
107 | 98, 106 | mt3d 148 |
. . . . . . . . . . 11
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → 𝑥 = ∅) |
108 | | el1o 8325 |
. . . . . . . . . . 11
⊢ (𝑥 ∈ 1o ↔
𝑥 =
∅) |
109 | 107, 108 | sylibr 233 |
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑊 = ∅) ∧ 𝑥 ∈ (𝐹 supp ∅)) → 𝑥 ∈ 1o) |
110 | 109 | ex 413 |
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑊 = ∅) → (𝑥 ∈ (𝐹 supp ∅) → 𝑥 ∈ 1o)) |
111 | 110 | ssrdv 3927 |
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑊 = ∅) → (𝐹 supp ∅) ⊆
1o) |
112 | 5, 55, 56, 57, 58, 60, 111 | cantnflt2 9431 |
. . . . . . 7
⊢ ((𝜑 ∧ 𝑊 = ∅) → ((ω CNF 𝐴)‘𝐹) ∈ (ω ↑o
1o)) |
113 | | oe1 8375 |
. . . . . . . 8
⊢ (ω
∈ On → (ω ↑o 1o) =
ω) |
114 | 6, 113 | ax-mp 5 |
. . . . . . 7
⊢ (ω
↑o 1o) = ω |
115 | 112, 114 | eleqtrdi 2849 |
. . . . . 6
⊢ ((𝜑 ∧ 𝑊 = ∅) → ((ω CNF 𝐴)‘𝐹) ∈ ω) |
116 | 54, 115 | eqeltrrd 2840 |
. . . . 5
⊢ ((𝜑 ∧ 𝑊 = ∅) → 𝐵 ∈ ω) |
117 | 116 | ex 413 |
. . . 4
⊢ (𝜑 → (𝑊 = ∅ → 𝐵 ∈ ω)) |
118 | 117 | necon3bd 2957 |
. . 3
⊢ (𝜑 → (¬ 𝐵 ∈ ω → 𝑊 ≠ ∅)) |
119 | 49, 118 | mpd 15 |
. 2
⊢ (𝜑 → 𝑊 ≠ ∅) |
120 | | dif1o 8330 |
. 2
⊢ (𝑊 ∈ (On ∖
1o) ↔ (𝑊
∈ On ∧ 𝑊 ≠
∅)) |
121 | 42, 119, 120 | sylanbrc 583 |
1
⊢ (𝜑 → 𝑊 ∈ (On ∖
1o)) |