Proof of Theorem closedsub
| Step | Hyp | Ref
| Expression |
| 1 | | elisset 1354 |
. 2
⊢ (H
∈ Cℋ → H
∈ V) |
| 2 | | elisset 1354 |
. . 3
⊢ (H
∈ Sℋ → H
∈ V) |
| 3 | 2 | adantr 306 |
. 2
⊢ ((H
∈ Sℋ ∧ ∀f∀x((f:ℕ–→H ∧ f
⇝v x) →
x ∈ H)) → H
∈ V) |
| 4 | | eleq1 1149 |
. . . 4
⊢ (h =
H → (h ∈ Sℋ ↔ H ∈ Sℋ )) |
| 5 | | feq3 2750 |
. . . . . . 7
⊢ (h =
H → (f:ℕ–→h ↔ f:ℕ–→H)) |
| 6 | 5 | anbi1d 469 |
. . . . . 6
⊢ (h =
H → ((f:ℕ–→h ∧ f
⇝v x) ↔
(f:ℕ–→H ∧ f
⇝v x))) |
| 7 | | eleq2 1150 |
. . . . . 6
⊢ (h =
H → (x ∈ h
↔ x ∈ H)) |
| 8 | 6, 7 | imbi12d 474 |
. . . . 5
⊢ (h =
H → (((f:ℕ–→h ∧ f
⇝v x) →
x ∈ h) ↔ ((f:ℕ–→H ∧ f
⇝v x) →
x ∈ H))) |
| 9 | 8 | bi2aldv 937 |
. . . 4
⊢ (h =
H → (∀f∀x((f:ℕ–→h ∧ f
⇝v x) →
x ∈ h) ↔ ∀f∀x((f:ℕ–→H ∧ f
⇝v x) →
x ∈ H))) |
| 10 | 4, 9 | anbi12d 476 |
. . 3
⊢ (h =
H → ((h ∈ Sℋ ∧
∀f∀x((f:ℕ–→h ∧ f
⇝v x) →
x ∈ h)) ↔ (H
∈ Sℋ ∧ ∀f∀x((f:ℕ–→H ∧ f
⇝v x) →
x ∈ H)))) |
| 11 | | df-ch 5127 |
. . 3
⊢ Cℋ = {h∣(h
∈ Sℋ ∧ ∀f∀x((f:ℕ–→h ∧ f
⇝v x) →
x ∈ h))} |
| 12 | 10, 11 | elab2g 1418 |
. 2
⊢ (H
∈ V → (H ∈
Cℋ ↔ (H ∈
Sℋ ∧ ∀f∀x((f:ℕ–→H ∧ f
⇝v x) →
x ∈ H)))) |
| 13 | 1, 3, 12 | pm5.21nii 504 |
1
⊢ (H
∈ Cℋ ↔ (H
∈ Sℋ ∧ ∀f∀x((f:ℕ–→H ∧ f
⇝v x) →
x ∈ H))) |