Step | Hyp | Ref
| Expression |
1 | | nclenc.1 |
. . . . 5
⊢ A ∈
V |
2 | 1 | ncelncsi 6122 |
. . . 4
⊢ Nc A ∈ NC |
3 | | nclenc.2 |
. . . . 5
⊢ B ∈
V |
4 | 3 | ncelncsi 6122 |
. . . 4
⊢ Nc B ∈ NC |
5 | | dflec3 6222 |
. . . 4
⊢ (( Nc A ∈ NC ∧ Nc B ∈ NC ) → ( Nc A ≤c Nc
B ↔ ∃p ∈ Nc A∃q ∈ Nc B∃g g:p–1-1→q)) |
6 | 2, 4, 5 | mp2an 653 |
. . 3
⊢ ( Nc A
≤c Nc B ↔ ∃p ∈ Nc A∃q ∈ Nc B∃g g:p–1-1→q) |
7 | | elnc 6126 |
. . . . . . . . 9
⊢ (p ∈ Nc A ↔ p ≈ A) |
8 | | bren 6031 |
. . . . . . . . 9
⊢ (p ≈ A
↔ ∃h h:p–1-1-onto→A) |
9 | 7, 8 | bitri 240 |
. . . . . . . 8
⊢ (p ∈ Nc A ↔ ∃h h:p–1-1-onto→A) |
10 | | elnc 6126 |
. . . . . . . . 9
⊢ (q ∈ Nc B ↔ q ≈ B) |
11 | | bren 6031 |
. . . . . . . . 9
⊢ (q ≈ B
↔ ∃i i:q–1-1-onto→B) |
12 | 10, 11 | bitri 240 |
. . . . . . . 8
⊢ (q ∈ Nc B ↔ ∃i i:q–1-1-onto→B) |
13 | 9, 12 | anbi12i 678 |
. . . . . . 7
⊢ ((p ∈ Nc A ∧ q ∈ Nc B) ↔ (∃h h:p–1-1-onto→A ∧ ∃i i:q–1-1-onto→B)) |
14 | | eeanv 1913 |
. . . . . . 7
⊢ (∃h∃i(h:p–1-1-onto→A ∧ i:q–1-1-onto→B) ↔
(∃h
h:p–1-1-onto→A ∧ ∃i i:q–1-1-onto→B)) |
15 | 13, 14 | bitr4i 243 |
. . . . . 6
⊢ ((p ∈ Nc A ∧ q ∈ Nc B) ↔ ∃h∃i(h:p–1-1-onto→A ∧ i:q–1-1-onto→B)) |
16 | | f1of1 5287 |
. . . . . . . . . . . 12
⊢ (i:q–1-1-onto→B →
i:q–1-1→B) |
17 | 16 | 3ad2ant2 977 |
. . . . . . . . . . 11
⊢ ((h:p–1-1-onto→A ∧ i:q–1-1-onto→B ∧ g:p–1-1→q) →
i:q–1-1→B) |
18 | | simp3 957 |
. . . . . . . . . . 11
⊢ ((h:p–1-1-onto→A ∧ i:q–1-1-onto→B ∧ g:p–1-1→q) →
g:p–1-1→q) |
19 | | f1co 5265 |
. . . . . . . . . . 11
⊢ ((i:q–1-1→B
∧ g:p–1-1→q)
→ (i ∘ g):p–1-1→B) |
20 | 17, 18, 19 | syl2anc 642 |
. . . . . . . . . 10
⊢ ((h:p–1-1-onto→A ∧ i:q–1-1-onto→B ∧ g:p–1-1→q) →
(i ∘
g):p–1-1→B) |
21 | | f1ocnv 5300 |
. . . . . . . . . . . 12
⊢ (h:p–1-1-onto→A →
◡h:A–1-1-onto→p) |
22 | | f1of1 5287 |
. . . . . . . . . . . 12
⊢ (◡h:A–1-1-onto→p →
◡h:A–1-1→p) |
23 | 21, 22 | syl 15 |
. . . . . . . . . . 11
⊢ (h:p–1-1-onto→A →
◡h:A–1-1→p) |
24 | 23 | 3ad2ant1 976 |
. . . . . . . . . 10
⊢ ((h:p–1-1-onto→A ∧ i:q–1-1-onto→B ∧ g:p–1-1→q) →
◡h:A–1-1→p) |
25 | | f1co 5265 |
. . . . . . . . . 10
⊢ (((i ∘ g):p–1-1→B
∧ ◡h:A–1-1→p)
→ ((i ∘ g) ∘ ◡h):A–1-1→B) |
26 | 20, 24, 25 | syl2anc 642 |
. . . . . . . . 9
⊢ ((h:p–1-1-onto→A ∧ i:q–1-1-onto→B ∧ g:p–1-1→q) →
((i ∘
g) ∘
◡h):A–1-1→B) |
27 | | vex 2863 |
. . . . . . . . . . . 12
⊢ i ∈
V |
28 | | vex 2863 |
. . . . . . . . . . . 12
⊢ g ∈
V |
29 | 27, 28 | coex 4751 |
. . . . . . . . . . 11
⊢ (i ∘ g) ∈
V |
30 | | vex 2863 |
. . . . . . . . . . . 12
⊢ h ∈
V |
31 | 30 | cnvex 5103 |
. . . . . . . . . . 11
⊢ ◡h ∈ V |
32 | 29, 31 | coex 4751 |
. . . . . . . . . 10
⊢ ((i ∘ g) ∘ ◡h) ∈ V |
33 | | f1eq1 5254 |
. . . . . . . . . 10
⊢ (f = ((i ∘ g) ∘ ◡h)
→ (f:A–1-1→B ↔
((i ∘
g) ∘
◡h):A–1-1→B)) |
34 | 32, 33 | spcev 2947 |
. . . . . . . . 9
⊢ (((i ∘ g) ∘ ◡h):A–1-1→B
→ ∃f f:A–1-1→B) |
35 | 26, 34 | syl 15 |
. . . . . . . 8
⊢ ((h:p–1-1-onto→A ∧ i:q–1-1-onto→B ∧ g:p–1-1→q) →
∃f
f:A–1-1→B) |
36 | 35 | 3expia 1153 |
. . . . . . 7
⊢ ((h:p–1-1-onto→A ∧ i:q–1-1-onto→B) →
(g:p–1-1→q →
∃f
f:A–1-1→B)) |
37 | 36 | exlimivv 1635 |
. . . . . 6
⊢ (∃h∃i(h:p–1-1-onto→A ∧ i:q–1-1-onto→B) →
(g:p–1-1→q →
∃f
f:A–1-1→B)) |
38 | 15, 37 | sylbi 187 |
. . . . 5
⊢ ((p ∈ Nc A ∧ q ∈ Nc B) → (g:p–1-1→q
→ ∃f f:A–1-1→B)) |
39 | 38 | exlimdv 1636 |
. . . 4
⊢ ((p ∈ Nc A ∧ q ∈ Nc B) → (∃g g:p–1-1→q
→ ∃f f:A–1-1→B)) |
40 | 39 | rexlimivv 2744 |
. . 3
⊢ (∃p ∈ Nc A∃q ∈ Nc B∃g g:p–1-1→q
→ ∃f f:A–1-1→B) |
41 | 6, 40 | sylbi 187 |
. 2
⊢ ( Nc A
≤c Nc B → ∃f f:A–1-1→B) |
42 | 1 | ncid 6124 |
. . . 4
⊢ A ∈ Nc A |
43 | 3 | ncid 6124 |
. . . 4
⊢ B ∈ Nc B |
44 | | f1eq2 5255 |
. . . . . 6
⊢ (a = A →
(f:a–1-1→b ↔
f:A–1-1→b)) |
45 | 44 | exbidv 1626 |
. . . . 5
⊢ (a = A →
(∃f
f:a–1-1→b ↔
∃f
f:A–1-1→b)) |
46 | | f1eq3 5256 |
. . . . . 6
⊢ (b = B →
(f:A–1-1→b ↔
f:A–1-1→B)) |
47 | 46 | exbidv 1626 |
. . . . 5
⊢ (b = B →
(∃f
f:A–1-1→b ↔
∃f
f:A–1-1→B)) |
48 | 45, 47 | rspc2ev 2964 |
. . . 4
⊢ ((A ∈ Nc A ∧ B ∈ Nc B ∧ ∃f f:A–1-1→B)
→ ∃a ∈ Nc A∃b ∈ Nc B∃f f:a–1-1→b) |
49 | 42, 43, 48 | mp3an12 1267 |
. . 3
⊢ (∃f f:A–1-1→B
→ ∃a ∈ Nc A∃b ∈ Nc B∃f f:a–1-1→b) |
50 | | dflec3 6222 |
. . . 4
⊢ (( Nc A ∈ NC ∧ Nc B ∈ NC ) → ( Nc A ≤c Nc
B ↔ ∃a ∈ Nc A∃b ∈ Nc B∃f f:a–1-1→b)) |
51 | 2, 4, 50 | mp2an 653 |
. . 3
⊢ ( Nc A
≤c Nc B ↔ ∃a ∈ Nc A∃b ∈ Nc B∃f f:a–1-1→b) |
52 | 49, 51 | sylibr 203 |
. 2
⊢ (∃f f:A–1-1→B
→ Nc A
≤c Nc B) |
53 | 41, 52 | impbii 180 |
1
⊢ ( Nc A
≤c Nc B ↔ ∃f f:A–1-1→B) |