Proof of Theorem inf3lemd
| Step | Hyp | Ref
| Expression |
| 1 | | nnsuc 2389 |
. . . 4
⊢ ((A
∈ ω ∧ ¬ A = ∅)
→ ∃v ∈ ω A = suc v) |
| 2 | | fveq2 2832 |
. . . . . . . 8
⊢ (A =
suc v → (F ‘A) =
(F ‘suc v)) |
| 3 | 2 | sseq1d 1527 |
. . . . . . 7
⊢ (A =
suc v → ((F ‘A)
⊆ x ↔ (F ‘suc v)
⊆ x)) |
| 4 | | inf3lem.1 |
. . . . . . . . . . 11
⊢ G =
{〈y, z〉∣z
= {w ∈ x∣(w ∩
x) ⊆ y}} |
| 5 | | inf3lem.2 |
. . . . . . . . . . 11
⊢ F =
(rec(G, ∅) ↾ ω) |
| 6 | | visset 1350 |
. . . . . . . . . . 11
⊢ v
∈ V |
| 7 | | inf3lem.4 |
. . . . . . . . . . 11
⊢ B
∈ V |
| 8 | 4, 5, 6, 7 | inf3lemc 3462 |
. . . . . . . . . 10
⊢ (v
∈ ω → (F ‘suc
v) = (G
‘(F ‘v))) |
| 9 | 8 | eleq2d 1156 |
. . . . . . . . 9
⊢ (v
∈ ω → (u ∈ (F ‘suc v)
↔ u ∈ (G ‘(F
‘v)))) |
| 10 | | visset 1350 |
. . . . . . . . . . 11
⊢ u
∈ V |
| 11 | | fvex 2838 |
. . . . . . . . . . 11
⊢ (F
‘v) ∈ V |
| 12 | 4, 5, 10, 11 | inf3lema 3460 |
. . . . . . . . . 10
⊢ (u
∈ (G ‘(F ‘v))
↔ (u ∈ x ∧ (u ∩
x) ⊆ (F ‘v))) |
| 13 | 12 | pm3.26bd 259 |
. . . . . . . . 9
⊢ (u
∈ (G ‘(F ‘v))
→ u ∈ x) |
| 14 | 9, 13 | syl6bi 187 |
. . . . . . . 8
⊢ (v
∈ ω → (u ∈ (F ‘suc v)
→ u ∈ x)) |
| 15 | 14 | ssrdv 1509 |
. . . . . . 7
⊢ (v
∈ ω → (F ‘suc
v) ⊆ x) |
| 16 | 3, 15 | syl5bir 184 |
. . . . . 6
⊢ (A =
suc v → (v ∈ ω → (F ‘A)
⊆ x)) |
| 17 | 16 | com12 13 |
. . . . 5
⊢ (v
∈ ω → (A = suc v → (F
‘A) ⊆ x)) |
| 18 | 17 | r19.23aiv 1284 |
. . . 4
⊢ (∃v ∈ ω A = suc v →
(F ‘A) ⊆ x) |
| 19 | 1, 18 | syl 12 |
. . 3
⊢ ((A
∈ ω ∧ ¬ A = ∅)
→ (F ‘A) ⊆ x) |
| 20 | 19 | exp 291 |
. 2
⊢ (A
∈ ω → (¬ A = ∅
→ (F ‘A) ⊆ x)) |
| 21 | | 0ss 1725 |
. . 3
⊢ ∅ ⊆ x |
| 22 | | fveq2 2832 |
. . . . 5
⊢ (A =
∅ → (F ‘A) = (F
‘∅)) |
| 23 | | inf3lem.3 |
. . . . . 6
⊢ A
∈ V |
| 24 | 4, 5, 23, 7 | inf3lemb 3461 |
. . . . 5
⊢ (F
‘∅) = ∅ |
| 25 | 22, 24 | syl6eq 1140 |
. . . 4
⊢ (A =
∅ → (F ‘A) = ∅) |
| 26 | 25 | sseq1d 1527 |
. . 3
⊢ (A =
∅ → ((F ‘A) ⊆ x
↔ ∅ ⊆ x)) |
| 27 | 21, 26 | mpbiri 169 |
. 2
⊢ (A =
∅ → (F ‘A) ⊆ x) |
| 28 | 20, 27 | pm2.61d2 111 |
1
⊢ (A
∈ ω → (F ‘A) ⊆ x) |