Proof of Theorem infxpidmlem2
| Step | Hyp | Ref
| Expression |
| 1 | | infxpidmlem2.2 |
. . 3
⊢ B
∈ V |
| 2 | | cleq1 1107 |
. . . 4
⊢ (f =
B → (f = ∅ ↔ B = ∅)) |
| 3 | | f1oeq1 2795 |
. . . . . 6
⊢ (f =
B → (f:(t ×
t)–1-1-onto→t ↔
B:(t
× t)–1-1-onto→t)) |
| 4 | 3 | anbi2d 468 |
. . . . 5
⊢ (f =
B → (((ω ≼ t ∧ t
⊆ A) ∧ f:(t ×
t)–1-1-onto→t) ↔
((ω ≼ t ∧ t ⊆ A)
∧ B:(t × t)–1-1-onto→t))) |
| 5 | 4 | biexdv 936 |
. . . 4
⊢ (f =
B → (∃t((ω ≼ t ∧ t
⊆ A) ∧ f:(t ×
t)–1-1-onto→t) ↔
∃t((ω ≼ t ∧ t
⊆ A) ∧ B:(t ×
t)–1-1-onto→t))) |
| 6 | 2, 5 | orbi12d 475 |
. . 3
⊢ (f =
B → ((f = ∅ ∨ ∃t((ω ≼ t ∧ t
⊆ A) ∧ f:(t ×
t)–1-1-onto→t)) ↔
(B = ∅ ∨ ∃t((ω ≼ t ∧ t
⊆ A) ∧ B:(t ×
t)–1-1-onto→t)))) |
| 7 | | infxpidmlem.1 |
. . 3
⊢ H =
{f∣(f = ∅ ∨ ∃t((ω ≼ t ∧ t
⊆ A) ∧ f:(t ×
t)–1-1-onto→t))} |
| 8 | 1, 6, 7 | elab2 1419 |
. 2
⊢ (B
∈ H ↔ (B = ∅ ∨ ∃t((ω ≼ t ∧ t
⊆ A) ∧ B:(t ×
t)–1-1-onto→t))) |
| 9 | | breq2 2066 |
. . . . . 6
⊢ (x =
t → (ω ≼ x ↔ ω ≼ t)) |
| 10 | | sseq1 1521 |
. . . . . 6
⊢ (x =
t → (x ⊆ A
↔ t ⊆ A)) |
| 11 | 9, 10 | anbi12d 476 |
. . . . 5
⊢ (x =
t → ((ω ≼ x ∧ x
⊆ A) ↔ (ω ≼ t ∧ t
⊆ A))) |
| 12 | | xpeq1 2440 |
. . . . . . . 8
⊢ (x =
t → (x × x) =
(t × x)) |
| 13 | | xpeq2 2441 |
. . . . . . . 8
⊢ (x =
t → (t × x) =
(t × t)) |
| 14 | 12, 13 | eqtrd 1128 |
. . . . . . 7
⊢ (x =
t → (x × x) =
(t × t)) |
| 15 | | f1oeq2 2796 |
. . . . . . 7
⊢ ((x
× x) = (t × t)
→ (B:(x × x)–1-1-onto→x ↔
B:(t
× t)–1-1-onto→x)) |
| 16 | 14, 15 | syl 12 |
. . . . . 6
⊢ (x =
t → (B:(x ×
x<.I>)–1-1-onto→x ↔
B:(t
× t)–1-1-onto→x)) |
| 17 | | f1oeq3 2797 |
. . . . . 6
⊢ (x =
t → (B:(t ×
t)–1-1-onto→x ↔
B:(t
× t)–1-1-onto→t)) |
| 18 | 16, 17 | bitrd 406 |
. . . . 5
⊢ (x =
t → (B:(x ×
x)–1-1-onto→x ↔
B:(t
× t)–1-1-onto→t)) |
| 19 | 11, 18 | anbi12d 476 |
. . . 4
⊢ (x =
t → (((ω ≼ x ∧ x
⊆ A) ∧ B:(x ×
x)–1-1-onto→x) ↔
((ω ≼ t ∧ t ⊆ A)
∧ B:(t × t)–1-1-onto→t))) |
| 20 | 19 | cbvexv 973 |
. . 3
⊢ (∃x((ω ≼ x ∧ x
⊆ A) ∧ B:(x ×
x)–1-1-onto→x) ↔
∃t((ω ≼ t ∧ t
⊆ A) ∧ B:(t ×
t)–1-1-onto→t)) |
| 21 | 20 | orbi2i 214 |
. 2
⊢ ((B =
∅ ∨ ∃x((ω ≼
x ∧ x ⊆ A)
∧ B:(x × x)–1-1-onto→x)) ↔
(B = ∅ ∨ ∃t((ω ≼ t ∧ t
⊆ A) ∧ B:(t ×
t)–1-1-onto→t))) |
| 22 | 8, 21 | bitr4 154 |
1
⊢ (B
∈ H ↔ (B = ∅ ∨ ∃x((ω ≼ x ∧ x
⊆ A) ∧ B:(x ×
x)–1-1-onto→x))) |