Proof of Theorem unidom
| Step | Hyp | Ref
| Expression |
| 1 | | unidom.1 |
. . . . . . 7
⊢ A ∈
V |
| 2 | 1 | uniex 2876 |
. . . . . 6
⊢ ∪A ∈ V |
| 3 | | id 59 |
. . . . . . . . . . . . . 14
⊢ (x = y →
x = y) |
| 4 | | fveq2 3730 |
. . . . . . . . . . . . . 14
⊢ (x = y →
(h ‘x) = (h
‘y)) |
| 5 | 3, 4 | eleq12d 1545 |
. . . . . . . . . . . . 13
⊢ (x = y →
(x ∈
(h ‘x) ↔ y
∈ (h
‘y))) |
| 6 | 4 | eleq1d 1543 |
. . . . . . . . . . . . 13
⊢ (x = y →
((h ‘x) ∈ A ↔ (h
‘y) ∈ A)) |
| 7 | 5, 6 | anbi12d 630 |
. . . . . . . . . . . 12
⊢ (x = y →
((x ∈
(h ‘x) ⋀ (h ‘x)
∈ A)
↔ (y ∈ (h
‘y) ⋀ (h
‘y) ∈ A))) |
| 8 | 7 | rcla4cv 1877 |
. . . . . . . . . . 11
⊢ (∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) →
(y ∈
∪A →
(y ∈
(h ‘y) ⋀ (h ‘y)
∈ A))) |
| 9 | | pm3.27 323 |
. . . . . . . . . . 11
⊢ ((y ∈ (h ‘y)
⋀ (h
‘y) ∈ A) →
(h ‘y) ∈ A) |
| 10 | 8, 9 | syl6 22 |
. . . . . . . . . 10
⊢ (∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) →
(y ∈
∪A →
(h ‘y) ∈ A)) |
| 11 | 10 | adantl 390 |
. . . . . . . . 9
⊢ ((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) →
(y ∈
∪A →
(h ‘y) ∈ A)) |
| 12 | | fveq2 3730 |
. . . . . . . . . . . . . . . . 17
⊢ (x = (h
‘y) → (f ‘x) =
(f ‘(h ‘y))) |
| 13 | | f1eq1 3666 |
. . . . . . . . . . . . . . . . 17
⊢ ((f ‘x) =
(f ‘(h ‘y))
→ ((f ‘x):x–1-1→B
↔ (f ‘(h ‘y)):x–1-1→B)) |
| 14 | 12, 13 | syl 10 |
. . . . . . . . . . . . . . . 16
⊢ (x = (h
‘y) → ((f ‘x):x–1-1→B
↔ (f ‘(h ‘y)):x–1-1→B)) |
| 15 | | f1eq2 3667 |
. . . . . . . . . . . . . . . 16
⊢ (x = (h
‘y) → ((f ‘(h
‘y)):x–1-1→B ↔
(f ‘(h ‘y)):(h
‘y)–1-1→B)) |
| 16 | 14, 15 | bitrd 530 |
. . . . . . . . . . . . . . 15
⊢ (x = (h
‘y) → ((f ‘x):x–1-1→B
↔ (f ‘(h ‘y)):(h
‘y)–1-1→B)) |
| 17 | 16 | rcla4v 1876 |
. . . . . . . . . . . . . 14
⊢ ((h ‘y)
∈ A
→ (∀x ∈ A (f
‘x):x–1-1→B →
(f ‘(h ‘y)):(h
‘y)–1-1→B)) |
| 18 | | f1f 3671 |
. . . . . . . . . . . . . 14
⊢ ((f ‘(h
‘y)):(h ‘y)–1-1→B →
(f ‘(h ‘y)):(h
‘y)–→B) |
| 19 | 17, 18 | syl6 22 |
. . . . . . . . . . . . 13
⊢ ((h ‘y)
∈ A
→ (∀x ∈ A (f
‘x):x–1-1→B →
(f ‘(h ‘y)):(h
‘y)–→B)) |
| 20 | | ffvelrn 3820 |
. . . . . . . . . . . . . 14
⊢ (((f ‘(h
‘y)):(h ‘y)–→B
⋀ y
∈ (h
‘y)) → ((f ‘(h
‘y)) ‘y) ∈ B) |
| 21 | 20 | expcom 374 |
. . . . . . . . . . . . 13
⊢ (y ∈ (h ‘y)
→ ((f ‘(h ‘y)):(h
‘y)–→B → ((f
‘(h ‘y)) ‘y)
∈ B)) |
| 22 | 19, 21 | sylan9r 471 |
. . . . . . . . . . . 12
⊢ ((y ∈ (h ‘y)
⋀ (h
‘y) ∈ A) →
(∀x
∈ A
(f ‘x):x–1-1→B
→ ((f ‘(h ‘y))
‘y) ∈ B)) |
| 23 | 8, 22 | syl6 22 |
. . . . . . . . . . 11
⊢ (∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) →
(y ∈
∪A → (∀x ∈ A (f ‘x):x–1-1→B
→ ((f ‘(h ‘y))
‘y) ∈ B))) |
| 24 | 23 | com3r 35 |
. . . . . . . . . 10
⊢ (∀x ∈ A (f ‘x):x–1-1→B
→ (∀x ∈ ∪A(x ∈ (h ‘x)
⋀ (h
‘x) ∈ A) →
(y ∈
∪A →
((f ‘(h ‘y))
‘y) ∈ B))) |
| 25 | 24 | imp 350 |
. . . . . . . . 9
⊢ ((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) →
(y ∈
∪A →
((f ‘(h ‘y))
‘y) ∈ B)) |
| 26 | 11, 25 | jcad 602 |
. . . . . . . 8
⊢ ((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) →
(y ∈
∪A →
((h ‘y) ∈ A ⋀ ((f ‘(h
‘y)) ‘y) ∈ B))) |
| 27 | | opelxpi 3223 |
. . . . . . . 8
⊢ (((h ‘y)
∈ A ⋀ ((f
‘(h ‘y)) ‘y)
∈ B)
→ 〈(h ‘y),
((f ‘(h ‘y))
‘y)〉 ∈ (A × B)) |
| 28 | 26, 27 | syl6 22 |
. . . . . . 7
⊢ ((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) →
(y ∈
∪A → 〈(h
‘y), ((f ‘(h
‘y)) ‘y)〉 ∈ (A ×
B))) |
| 29 | | fveq2 3730 |
. . . . . . . . . . . . . . 15
⊢ ((h ‘y) =
(h ‘z) → (f
‘(h ‘y)) = (f
‘(h ‘z))) |
| 30 | 29 | fveq1d 3732 |
. . . . . . . . . . . . . 14
⊢ ((h ‘y) =
(h ‘z) → ((f
‘(h ‘y)) ‘z) =
((f ‘(h ‘z))
‘z)) |
| 31 | 30 | eqeq2d 1489 |
. . . . . . . . . . . . 13
⊢ ((h ‘y) =
(h ‘z) → (((f
‘(h ‘y)) ‘y) =
((f ‘(h ‘y))
‘z) ↔ ((f ‘(h
‘y)) ‘y) = ((f
‘(h ‘z)) ‘z))) |
| 32 | 31 | adantl 390 |
. . . . . . . . . . . 12
⊢ ((((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) ⋀ (h
‘y) = (h ‘z))
→ (((f ‘(h ‘y))
‘y) = ((f ‘(h
‘y)) ‘z) ↔ ((f
‘(h ‘y)) ‘y) =
((f ‘(h ‘z))
‘z))) |
| 33 | | f1fveq 3882 |
. . . . . . . . . . . . . 14
⊢ (((f ‘(h
‘y)):(h ‘y)–1-1→B ⋀ (y ∈ (h
‘y) ⋀ z ∈ (h
‘y))) → (((f ‘(h
‘y)) ‘y) = ((f
‘(h ‘y)) ‘z)
↔ y = z)) |
| 34 | 33 | biimpd 153 |
. . . . . . . . . . . . 13
⊢ (((f ‘(h
‘y)):(h ‘y)–1-1→B ⋀ (y ∈ (h
‘y) ⋀ z ∈ (h
‘y))) → (((f ‘(h
‘y)) ‘y) = ((f
‘(h ‘y)) ‘z)
→ y = z)) |
| 35 | 17 | adantl 390 |
. . . . . . . . . . . . . . . . . 18
⊢ ((y ∈ (h ‘y)
⋀ (h
‘y) ∈ A) →
(∀x
∈ A
(f ‘x):x–1-1→B
→ (f ‘(h ‘y)):(h
‘y)–1-1→B)) |
| 36 | 8, 35 | syl6 22 |
. . . . . . . . . . . . . . . . 17
⊢ (∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) →
(y ∈
∪A → (∀x ∈ A (f ‘x):x–1-1→B
→ (f ‘(h ‘y)):(h
‘y)–1-1→B))) |
| 37 | 36 | com3r 35 |
. . . . . . . . . . . . . . . 16
⊢ (∀x ∈ A (f ‘x):x–1-1→B
→ (∀x ∈ ∪A(x ∈ (h ‘x)
⋀ (h
‘x) ∈ A) →
(y ∈
∪A →
(f ‘(h ‘y)):(h
‘y)–1-1→B))) |
| 38 | 37 | imp31 362 |
. . . . . . . . . . . . . . 15
⊢ (((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ y ∈ ∪A) → (f
‘(h ‘y)):(h
‘y)–1-1→B) |
| 39 | 38 | adantrr 397 |
. . . . . . . . . . . . . 14
⊢ (((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) → (f ‘(h
‘y)):(h ‘y)–1-1→B) |
| 40 | 39 | adantr 391 |
. . . . . . . . . . . . 13
⊢ ((((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) ⋀ (h
‘y) = (h ‘z))
→ (f ‘(h ‘y)):(h
‘y)–1-1→B) |
| 41 | | pm3.26 319 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((y ∈ (h ‘y)
⋀ (h
‘y) ∈ A) →
y ∈
(h ‘y)) |
| 42 | 8, 41 | syl6 22 |
. . . . . . . . . . . . . . . . . 18
⊢ (∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) →
(y ∈
∪A →
y ∈
(h ‘y))) |
| 43 | 42 | adantr 391 |
. . . . . . . . . . . . . . . . 17
⊢ ((∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) ⋀ (h
‘y) = (h ‘z))
→ (y ∈ ∪A → y ∈ (h
‘y))) |
| 44 | | id 59 |
. . . . . . . . . . . . . . . . . . . . . 22
⊢ (x = z →
x = z) |
| 45 | | fveq2 3730 |
. . . . . . . . . . . . . . . . . . . . . 22
⊢ (x = z →
(h ‘x) = (h
‘z)) |
| 46 | 44, 45 | eleq12d 1545 |
. . . . . . . . . . . . . . . . . . . . 21
⊢ (x = z →
(x ∈
(h ‘x) ↔ z
∈ (h
‘z))) |
| 47 | 45 | eleq1d 1543 |
. . . . . . . . . . . . . . . . . . . . 21
⊢ (x = z →
((h ‘x) ∈ A ↔ (h
‘z) ∈ A)) |
| 48 | 46, 47 | anbi12d 630 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (x = z →
((x ∈
(h ‘x) ⋀ (h ‘x)
∈ A)
↔ (z ∈ (h
‘z) ⋀ (h
‘z) ∈ A))) |
| 49 | 48 | rcla4cv 1877 |
. . . . . . . . . . . . . . . . . . 19
⊢ (∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) →
(z ∈
∪A →
(z ∈
(h ‘z) ⋀ (h ‘z)
∈ A))) |
| 50 | | pm3.26 319 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((z ∈ (h ‘z)
⋀ (h
‘z) ∈ A) →
z ∈
(h ‘z)) |
| 51 | 49, 50 | syl6 22 |
. . . . . . . . . . . . . . . . . 18
⊢ (∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) →
(z ∈
∪A →
z ∈
(h ‘z))) |
| 52 | | eleq2 1538 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((h ‘y) =
(h ‘z) → (z
∈ (h
‘y) ↔ z ∈ (h ‘z))) |
| 53 | 52 | biimprd 154 |
. . . . . . . . . . . . . . . . . 18
⊢ ((h ‘y) =
(h ‘z) → (z
∈ (h
‘z) → z ∈ (h ‘y))) |
| 54 | 51, 53 | sylan9 470 |
. . . . . . . . . . . . . . . . 17
⊢ ((∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) ⋀ (h
‘y) = (h ‘z))
→ (z ∈ ∪A → z ∈ (h
‘y))) |
| 55 | 43, 54 | anim12d 560 |
. . . . . . . . . . . . . . . 16
⊢ ((∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) ⋀ (h
‘y) = (h ‘z))
→ ((y ∈ ∪A ⋀ z ∈ ∪A) → (y ∈ (h ‘y)
⋀ z
∈ (h
‘y)))) |
| 56 | 55 | imp 350 |
. . . . . . . . . . . . . . 15
⊢ (((∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) ⋀ (h
‘y) = (h ‘z))
⋀ (y
∈ ∪A ⋀ z ∈ ∪A)) → (y ∈ (h ‘y)
⋀ z
∈ (h
‘y))) |
| 57 | 56 | an1rs 491 |
. . . . . . . . . . . . . 14
⊢ (((∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) ⋀ (h
‘y) = (h ‘z))
→ (y ∈ (h
‘y) ⋀ z ∈ (h
‘y))) |
| 58 | 57 | adantlll 398 |
. . . . . . . . . . . . 13
⊢ ((((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) ⋀ (h
‘y) = (h ‘z))
→ (y ∈ (h
‘y) ⋀ z ∈ (h
‘y))) |
| 59 | 34, 40, 58 | sylanc 473 |
. . . . . . . . . . . 12
⊢ ((((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) ⋀ (h
‘y) = (h ‘z))
→ (((f ‘(h ‘y))
‘y) = ((f ‘(h
‘y)) ‘z) → y =
z)) |
| 60 | 32, 59 | sylbird 205 |
. . . . . . . . . . 11
⊢ ((((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) ⋀ (h
‘y) = (h ‘z))
→ (((f ‘(h ‘y))
‘y) = ((f ‘(h
‘z)) ‘z) → y =
z)) |
| 61 | 60 | expimpd 375 |
. . . . . . . . . 10
⊢ (((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) →
(((h ‘y) = (h
‘z) ⋀ ((f
‘(h ‘y)) ‘y) =
((f ‘(h ‘z))
‘z)) → y = z)) |
| 62 | | fvex 3738 |
. . . . . . . . . . 11
⊢ (h ‘y)
∈ V |
| 63 | | fvex 3738 |
. . . . . . . . . . 11
⊢ ((f ‘(h
‘y)) ‘y) ∈
V |
| 64 | | fvex 3738 |
. . . . . . . . . . 11
⊢ ((f ‘(h
‘z)) ‘z) ∈
V |
| 65 | 62, 63, 64 | opth 2793 |
. . . . . . . . . 10
⊢ (〈(h
‘y), ((f ‘(h
‘y)) ‘y)〉 = 〈(h
‘z), ((f ‘(h
‘z)) ‘z)〉 ↔
((h ‘y) = (h
‘z) ⋀ ((f
‘(h ‘y)) ‘y) =
((f ‘(h ‘z))
‘z))) |
| 66 | 61, 65 | syl5ib 206 |
. . . . . . . . 9
⊢ (((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) → (〈(h
‘y), ((f ‘(h
‘y)) ‘y)〉 = 〈(h
‘z), ((f ‘(h
‘z)) ‘z)〉 →
y = z)) |
| 67 | | fveq2 3730 |
. . . . . . . . . 10
⊢ (y = z →
(h ‘y) = (h
‘z)) |
| 68 | 67 | fveq2d 3734 |
. . . . . . . . . . . 12
⊢ (y = z →
(f ‘(h ‘y)) =
(f ‘(h ‘z))) |
| 69 | 68 | fveq1d 3732 |
. . . . . . . . . . 11
⊢ (y = z →
((f ‘(h ‘y))
‘y) = ((f ‘(h
‘z)) ‘y)) |
| 70 | | fveq2 3730 |
. . . . . . . . . . 11
⊢ (y = z →
((f ‘(h ‘z))
‘y) = ((f ‘(h
‘z)) ‘z)) |
| 71 | 69, 70 | eqtrd 1510 |
. . . . . . . . . 10
⊢ (y = z →
((f ‘(h ‘y))
‘y) = ((f ‘(h
‘z)) ‘z)) |
| 72 | 67, 71 | opeq12d 2499 |
. . . . . . . . 9
⊢ (y = z →
〈(h
‘y), ((f ‘(h
‘y)) ‘y)〉 = 〈(h
‘z), ((f ‘(h
‘z)) ‘z)〉) |
| 73 | 66, 72 | impbid1 519 |
. . . . . . . 8
⊢ (((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) ⋀ (y ∈ ∪A ⋀ z ∈ ∪A)) → (〈(h
‘y), ((f ‘(h
‘y)) ‘y)〉 = 〈(h
‘z), ((f ‘(h
‘z)) ‘z)〉 ↔
y = z)) |
| 74 | 73 | ex 373 |
. . . . . . 7
⊢ ((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) →
((y ∈
∪A ⋀ z ∈ ∪A) → (〈(h
‘y), ((f ‘(h
‘y)) ‘y)〉 = 〈(h
‘z), ((f ‘(h
‘z)) ‘z)〉 ↔
y = z))) |
| 75 | 28, 74 | dom2d 4410 |
. . . . . 6
⊢ ((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) →
(∪A ∈ V → ∪A ≼ (A ×
B))) |
| 76 | 2, 75 | mpi 44 |
. . . . 5
⊢ ((∀x ∈ A (f ‘x):x–1-1→B
⋀ ∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) →
∪A ≼ (A ×
B)) |
| 77 | 76 | ex 373 |
. . . 4
⊢ (∀x ∈ A (f ‘x):x–1-1→B
→ (∀x ∈ ∪A(x ∈ (h ‘x)
⋀ (h
‘x) ∈ A) →
∪A ≼ (A ×
B))) |
| 78 | 77 | 19.23adv 1216 |
. . 3
⊢ (∀x ∈ A (f ‘x):x–1-1→B
→ (∃h∀x ∈ ∪A(x ∈ (h ‘x)
⋀ (h
‘x) ∈ A) →
∪A ≼ (A ×
B))) |
| 79 | 78 | 19.23aiv 1297 |
. 2
⊢ (∃f∀x ∈ A (f ‘x):x–1-1→B
→ (∃h∀x ∈ ∪A(x ∈ (h ‘x)
⋀ (h
‘x) ∈ A) →
∪A ≼ (A ×
B))) |
| 80 | | unidom.2 |
. . . . 5
⊢ B ∈
V |
| 81 | 80 | brdom 4384 |
. . . 4
⊢ (x ≼ B ↔ ∃g g:x–1-1→B) |
| 82 | 81 | ralbii 1670 |
. . 3
⊢ (∀x ∈ A x ≼ B ↔ ∀x ∈ A ∃g g:x–1-1→B) |
| 83 | | f1eq1 3666 |
. . . 4
⊢ (g = (f
‘x) → (g:x–1-1→B
↔ (f ‘x):x–1-1→B)) |
| 84 | 1, 83 | ac6s3 4769 |
. . 3
⊢ (∀x ∈ A ∃g g:x–1-1→B
→ ∃f∀x ∈ A (f
‘x):x–1-1→B) |
| 85 | 82, 84 | sylbi 199 |
. 2
⊢ (∀x ∈ A x ≼ B → ∃f∀x ∈ A (f ‘x):x–1-1→B) |
| 86 | | eleq2 1538 |
. . . . . 6
⊢ (g = (h
‘x) → (x ∈ g ↔ x ∈ (h
‘x))) |
| 87 | | eleq1 1537 |
. . . . . 6
⊢ (g = (h
‘x) → (g ∈ A ↔ (h
‘x) ∈ A)) |
| 88 | 86, 87 | anbi12d 630 |
. . . . 5
⊢ (g = (h
‘x) → ((x ∈ g ⋀ g ∈ A) ↔ (x
∈ (h
‘x) ⋀ (h
‘x) ∈ A))) |
| 89 | 2, 88 | ac6s3 4769 |
. . . 4
⊢ (∀x ∈ ∪A∃g(x ∈ g ⋀ g ∈ A) →
∃h∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) |
| 90 | | eluni 2510 |
. . . . 5
⊢ (x ∈ ∪A ↔ ∃g(x ∈ g ⋀ g ∈ A)) |
| 91 | 90 | biimp 151 |
. . . 4
⊢ (x ∈ ∪A → ∃g(x ∈ g ⋀ g ∈ A)) |
| 92 | 89, 91 | mprg 1703 |
. . 3
⊢ ∃h∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A) |
| 93 | 92 | a1i 8 |
. 2
⊢ (∀x ∈ A x ≼ B → ∃h∀x ∈ ∪A(x ∈ (h
‘x) ⋀ (h
‘x) ∈ A)) |
| 94 | 79, 85, 93 | sylc 68 |
1
⊢ (∀x ∈ A x ≼ B → ∪A ≼ (A × B)) |