Step | Hyp | Ref
| Expression |
1 | | brwdom3i 9272 |
. . 3
⊢ (𝐴 ≼* 𝐵 → ∃𝑓∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏)) |
2 | 1 | 3ad2ant1 1131 |
. 2
⊢ ((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) → ∃𝑓∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏)) |
3 | | brwdom3i 9272 |
. . . . 5
⊢ (𝐶 ≼* 𝐷 → ∃𝑔∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏)) |
4 | 3 | 3ad2ant2 1132 |
. . . 4
⊢ ((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) → ∃𝑔∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏)) |
5 | 4 | adantr 480 |
. . 3
⊢ (((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) ∧ ∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏)) → ∃𝑔∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏)) |
6 | | relwdom 9255 |
. . . . . . . . . 10
⊢ Rel
≼* |
7 | 6 | brrelex1i 5634 |
. . . . . . . . 9
⊢ (𝐴 ≼* 𝐵 → 𝐴 ∈ V) |
8 | 6 | brrelex1i 5634 |
. . . . . . . . 9
⊢ (𝐶 ≼* 𝐷 → 𝐶 ∈ V) |
9 | | unexg 7577 |
. . . . . . . . 9
⊢ ((𝐴 ∈ V ∧ 𝐶 ∈ V) → (𝐴 ∪ 𝐶) ∈ V) |
10 | 7, 8, 9 | syl2an 595 |
. . . . . . . 8
⊢ ((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷) → (𝐴 ∪ 𝐶) ∈ V) |
11 | 10 | 3adant3 1130 |
. . . . . . 7
⊢ ((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) → (𝐴 ∪ 𝐶) ∈ V) |
12 | 11 | adantr 480 |
. . . . . 6
⊢ (((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) ∧ (∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏))) → (𝐴 ∪ 𝐶) ∈ V) |
13 | 6 | brrelex2i 5635 |
. . . . . . . . 9
⊢ (𝐴 ≼* 𝐵 → 𝐵 ∈ V) |
14 | 6 | brrelex2i 5635 |
. . . . . . . . 9
⊢ (𝐶 ≼* 𝐷 → 𝐷 ∈ V) |
15 | | unexg 7577 |
. . . . . . . . 9
⊢ ((𝐵 ∈ V ∧ 𝐷 ∈ V) → (𝐵 ∪ 𝐷) ∈ V) |
16 | 13, 14, 15 | syl2an 595 |
. . . . . . . 8
⊢ ((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷) → (𝐵 ∪ 𝐷) ∈ V) |
17 | 16 | 3adant3 1130 |
. . . . . . 7
⊢ ((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) → (𝐵 ∪ 𝐷) ∈ V) |
18 | 17 | adantr 480 |
. . . . . 6
⊢ (((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) ∧ (∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏))) → (𝐵 ∪ 𝐷) ∈ V) |
19 | | elun 4079 |
. . . . . . . . . 10
⊢ (𝑦 ∈ (𝐴 ∪ 𝐶) ↔ (𝑦 ∈ 𝐴 ∨ 𝑦 ∈ 𝐶)) |
20 | | eqeq1 2742 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑎 = 𝑦 → (𝑎 = (𝑓‘𝑏) ↔ 𝑦 = (𝑓‘𝑏))) |
21 | 20 | rexbidv 3225 |
. . . . . . . . . . . . . . . 16
⊢ (𝑎 = 𝑦 → (∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ↔ ∃𝑏 ∈ 𝐵 𝑦 = (𝑓‘𝑏))) |
22 | 21 | rspcva 3550 |
. . . . . . . . . . . . . . 15
⊢ ((𝑦 ∈ 𝐴 ∧ ∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏)) → ∃𝑏 ∈ 𝐵 𝑦 = (𝑓‘𝑏)) |
23 | | fveq2 6756 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑏 = 𝑧 → (𝑓‘𝑏) = (𝑓‘𝑧)) |
24 | 23 | eqeq2d 2749 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑏 = 𝑧 → (𝑦 = (𝑓‘𝑏) ↔ 𝑦 = (𝑓‘𝑧))) |
25 | 24 | cbvrexvw 3373 |
. . . . . . . . . . . . . . . 16
⊢
(∃𝑏 ∈
𝐵 𝑦 = (𝑓‘𝑏) ↔ ∃𝑧 ∈ 𝐵 𝑦 = (𝑓‘𝑧)) |
26 | | ssun1 4102 |
. . . . . . . . . . . . . . . . 17
⊢ 𝐵 ⊆ (𝐵 ∪ 𝐷) |
27 | | iftrue 4462 |
. . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑧 ∈ 𝐵 → if(𝑧 ∈ 𝐵, 𝑓, 𝑔) = 𝑓) |
28 | 27 | fveq1d 6758 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑧 ∈ 𝐵 → (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧) = (𝑓‘𝑧)) |
29 | 28 | eqeq2d 2749 |
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑧 ∈ 𝐵 → (𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧) ↔ 𝑦 = (𝑓‘𝑧))) |
30 | 29 | biimprd 247 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑧 ∈ 𝐵 → (𝑦 = (𝑓‘𝑧) → 𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧))) |
31 | 30 | reximia 3172 |
. . . . . . . . . . . . . . . . 17
⊢
(∃𝑧 ∈
𝐵 𝑦 = (𝑓‘𝑧) → ∃𝑧 ∈ 𝐵 𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
32 | | ssrexv 3984 |
. . . . . . . . . . . . . . . . 17
⊢ (𝐵 ⊆ (𝐵 ∪ 𝐷) → (∃𝑧 ∈ 𝐵 𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧))) |
33 | 26, 31, 32 | mpsyl 68 |
. . . . . . . . . . . . . . . 16
⊢
(∃𝑧 ∈
𝐵 𝑦 = (𝑓‘𝑧) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
34 | 25, 33 | sylbi 216 |
. . . . . . . . . . . . . . 15
⊢
(∃𝑏 ∈
𝐵 𝑦 = (𝑓‘𝑏) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
35 | 22, 34 | syl 17 |
. . . . . . . . . . . . . 14
⊢ ((𝑦 ∈ 𝐴 ∧ ∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏)) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
36 | 35 | ancoms 458 |
. . . . . . . . . . . . 13
⊢
((∀𝑎 ∈
𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ 𝑦 ∈ 𝐴) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
37 | 36 | adantlr 711 |
. . . . . . . . . . . 12
⊢
(((∀𝑎 ∈
𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏)) ∧ 𝑦 ∈ 𝐴) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
38 | 37 | adantll 710 |
. . . . . . . . . . 11
⊢ ((((𝐵 ∩ 𝐷) = ∅ ∧ (∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏))) ∧ 𝑦 ∈ 𝐴) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
39 | | eqeq1 2742 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑎 = 𝑦 → (𝑎 = (𝑔‘𝑏) ↔ 𝑦 = (𝑔‘𝑏))) |
40 | 39 | rexbidv 3225 |
. . . . . . . . . . . . . . . 16
⊢ (𝑎 = 𝑦 → (∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏) ↔ ∃𝑏 ∈ 𝐷 𝑦 = (𝑔‘𝑏))) |
41 | | fveq2 6756 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑏 = 𝑧 → (𝑔‘𝑏) = (𝑔‘𝑧)) |
42 | 41 | eqeq2d 2749 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑏 = 𝑧 → (𝑦 = (𝑔‘𝑏) ↔ 𝑦 = (𝑔‘𝑧))) |
43 | 42 | cbvrexvw 3373 |
. . . . . . . . . . . . . . . 16
⊢
(∃𝑏 ∈
𝐷 𝑦 = (𝑔‘𝑏) ↔ ∃𝑧 ∈ 𝐷 𝑦 = (𝑔‘𝑧)) |
44 | 40, 43 | bitrdi 286 |
. . . . . . . . . . . . . . 15
⊢ (𝑎 = 𝑦 → (∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏) ↔ ∃𝑧 ∈ 𝐷 𝑦 = (𝑔‘𝑧))) |
45 | 44 | rspccva 3551 |
. . . . . . . . . . . . . 14
⊢
((∀𝑎 ∈
𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏) ∧ 𝑦 ∈ 𝐶) → ∃𝑧 ∈ 𝐷 𝑦 = (𝑔‘𝑧)) |
46 | | ssun2 4103 |
. . . . . . . . . . . . . . 15
⊢ 𝐷 ⊆ (𝐵 ∪ 𝐷) |
47 | | minel 4396 |
. . . . . . . . . . . . . . . . . . . . . 22
⊢ ((𝑧 ∈ 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) → ¬ 𝑧 ∈ 𝐵) |
48 | 47 | ancoms 458 |
. . . . . . . . . . . . . . . . . . . . 21
⊢ (((𝐵 ∩ 𝐷) = ∅ ∧ 𝑧 ∈ 𝐷) → ¬ 𝑧 ∈ 𝐵) |
49 | 48 | iffalsed 4467 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (((𝐵 ∩ 𝐷) = ∅ ∧ 𝑧 ∈ 𝐷) → if(𝑧 ∈ 𝐵, 𝑓, 𝑔) = 𝑔) |
50 | 49 | fveq1d 6758 |
. . . . . . . . . . . . . . . . . . 19
⊢ (((𝐵 ∩ 𝐷) = ∅ ∧ 𝑧 ∈ 𝐷) → (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧) = (𝑔‘𝑧)) |
51 | 50 | eqeq2d 2749 |
. . . . . . . . . . . . . . . . . 18
⊢ (((𝐵 ∩ 𝐷) = ∅ ∧ 𝑧 ∈ 𝐷) → (𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧) ↔ 𝑦 = (𝑔‘𝑧))) |
52 | 51 | biimprd 247 |
. . . . . . . . . . . . . . . . 17
⊢ (((𝐵 ∩ 𝐷) = ∅ ∧ 𝑧 ∈ 𝐷) → (𝑦 = (𝑔‘𝑧) → 𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧))) |
53 | 52 | reximdva 3202 |
. . . . . . . . . . . . . . . 16
⊢ ((𝐵 ∩ 𝐷) = ∅ → (∃𝑧 ∈ 𝐷 𝑦 = (𝑔‘𝑧) → ∃𝑧 ∈ 𝐷 𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧))) |
54 | 53 | imp 406 |
. . . . . . . . . . . . . . 15
⊢ (((𝐵 ∩ 𝐷) = ∅ ∧ ∃𝑧 ∈ 𝐷 𝑦 = (𝑔‘𝑧)) → ∃𝑧 ∈ 𝐷 𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
55 | | ssrexv 3984 |
. . . . . . . . . . . . . . 15
⊢ (𝐷 ⊆ (𝐵 ∪ 𝐷) → (∃𝑧 ∈ 𝐷 𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧))) |
56 | 46, 54, 55 | mpsyl 68 |
. . . . . . . . . . . . . 14
⊢ (((𝐵 ∩ 𝐷) = ∅ ∧ ∃𝑧 ∈ 𝐷 𝑦 = (𝑔‘𝑧)) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
57 | 45, 56 | sylan2 592 |
. . . . . . . . . . . . 13
⊢ (((𝐵 ∩ 𝐷) = ∅ ∧ (∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏) ∧ 𝑦 ∈ 𝐶)) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
58 | 57 | anassrs 467 |
. . . . . . . . . . . 12
⊢ ((((𝐵 ∩ 𝐷) = ∅ ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏)) ∧ 𝑦 ∈ 𝐶) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
59 | 58 | adantlrl 716 |
. . . . . . . . . . 11
⊢ ((((𝐵 ∩ 𝐷) = ∅ ∧ (∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏))) ∧ 𝑦 ∈ 𝐶) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
60 | 38, 59 | jaodan 954 |
. . . . . . . . . 10
⊢ ((((𝐵 ∩ 𝐷) = ∅ ∧ (∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏))) ∧ (𝑦 ∈ 𝐴 ∨ 𝑦 ∈ 𝐶)) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
61 | 19, 60 | sylan2b 593 |
. . . . . . . . 9
⊢ ((((𝐵 ∩ 𝐷) = ∅ ∧ (∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏))) ∧ 𝑦 ∈ (𝐴 ∪ 𝐶)) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
62 | 61 | expl 457 |
. . . . . . . 8
⊢ ((𝐵 ∩ 𝐷) = ∅ → (((∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏)) ∧ 𝑦 ∈ (𝐴 ∪ 𝐶)) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧))) |
63 | 62 | 3ad2ant3 1133 |
. . . . . . 7
⊢ ((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) → (((∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏)) ∧ 𝑦 ∈ (𝐴 ∪ 𝐶)) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧))) |
64 | 63 | impl 455 |
. . . . . 6
⊢ ((((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) ∧ (∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏))) ∧ 𝑦 ∈ (𝐴 ∪ 𝐶)) → ∃𝑧 ∈ (𝐵 ∪ 𝐷)𝑦 = (if(𝑧 ∈ 𝐵, 𝑓, 𝑔)‘𝑧)) |
65 | 12, 18, 64 | wdom2d 9269 |
. . . . 5
⊢ (((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) ∧ (∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏) ∧ ∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏))) → (𝐴 ∪ 𝐶) ≼* (𝐵 ∪ 𝐷)) |
66 | 65 | expr 456 |
. . . 4
⊢ (((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) ∧ ∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏)) → (∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏) → (𝐴 ∪ 𝐶) ≼* (𝐵 ∪ 𝐷))) |
67 | 66 | exlimdv 1937 |
. . 3
⊢ (((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) ∧ ∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏)) → (∃𝑔∀𝑎 ∈ 𝐶 ∃𝑏 ∈ 𝐷 𝑎 = (𝑔‘𝑏) → (𝐴 ∪ 𝐶) ≼* (𝐵 ∪ 𝐷))) |
68 | 5, 67 | mpd 15 |
. 2
⊢ (((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) ∧ ∀𝑎 ∈ 𝐴 ∃𝑏 ∈ 𝐵 𝑎 = (𝑓‘𝑏)) → (𝐴 ∪ 𝐶) ≼* (𝐵 ∪ 𝐷)) |
69 | 2, 68 | exlimddv 1939 |
1
⊢ ((𝐴 ≼* 𝐵 ∧ 𝐶 ≼* 𝐷 ∧ (𝐵 ∩ 𝐷) = ∅) → (𝐴 ∪ 𝐶) ≼* (𝐵 ∪ 𝐷)) |