| Step | Hyp | Ref
| Expression |
| 1 | | snex 4112 |
. . . . 5
⊢ {x} ∈
V |
| 2 | | eleq1 2413 |
. . . . . 6
⊢ (t = {x} →
(t ∈
𝒫1A ↔ {x} ∈
𝒫1A)) |
| 3 | | eleq1 2413 |
. . . . . 6
⊢ (t = {x} →
(t ∈
𝒫1B ↔ {x} ∈
𝒫1B)) |
| 4 | 2, 3 | bibi12d 312 |
. . . . 5
⊢ (t = {x} →
((t ∈
𝒫1A ↔ t ∈
𝒫1B) ↔ ({x} ∈
𝒫1A ↔ {x} ∈
𝒫1B))) |
| 5 | 1, 4 | ceqsalv 2886 |
. . . 4
⊢ (∀t(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B)) ↔ ({x} ∈
𝒫1A ↔ {x} ∈
𝒫1B)) |
| 6 | | snelpw1 4147 |
. . . . 5
⊢ ({x} ∈
𝒫1A ↔ x ∈ A) |
| 7 | | snelpw1 4147 |
. . . . 5
⊢ ({x} ∈
𝒫1B ↔ x ∈ B) |
| 8 | 6, 7 | bibi12i 306 |
. . . 4
⊢ (({x} ∈
𝒫1A ↔ {x} ∈
𝒫1B) ↔ (x ∈ A ↔ x ∈ B)) |
| 9 | 5, 8 | bitri 240 |
. . 3
⊢ (∀t(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B)) ↔ (x ∈ A ↔ x ∈ B)) |
| 10 | 9 | albii 1566 |
. 2
⊢ (∀x∀t(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B)) ↔ ∀x(x ∈ A ↔ x ∈ B)) |
| 11 | | pw1ss1c 4159 |
. . . 4
⊢
𝒫1A ⊆ 1c |
| 12 | | pw1ss1c 4159 |
. . . 4
⊢
𝒫1B ⊆ 1c |
| 13 | | ssofeq 4078 |
. . . 4
⊢
((𝒫1A ⊆ 1c ∧
𝒫1B ⊆ 1c) →
(𝒫1A =
𝒫1B ↔ ∀t ∈ 1c (t ∈
𝒫1A ↔ t ∈
𝒫1B))) |
| 14 | 11, 12, 13 | mp2an 653 |
. . 3
⊢
(𝒫1A =
𝒫1B ↔ ∀t ∈ 1c (t ∈
𝒫1A ↔ t ∈
𝒫1B)) |
| 15 | | df-ral 2620 |
. . . 4
⊢ (∀t ∈ 1c (t ∈
𝒫1A ↔ t ∈
𝒫1B) ↔ ∀t(t ∈ 1c
→ (t ∈ 𝒫1A ↔ t ∈ 𝒫1B))) |
| 16 | | el1c 4140 |
. . . . . . . 8
⊢ (t ∈ 1c
↔ ∃x t = {x}) |
| 17 | 16 | imbi1i 315 |
. . . . . . 7
⊢ ((t ∈ 1c
→ (t ∈ 𝒫1A ↔ t ∈ 𝒫1B)) ↔ (∃x t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B))) |
| 18 | | 19.23v 1891 |
. . . . . . 7
⊢ (∀x(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B)) ↔ (∃x t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B))) |
| 19 | 17, 18 | bitr4i 243 |
. . . . . 6
⊢ ((t ∈ 1c
→ (t ∈ 𝒫1A ↔ t ∈ 𝒫1B)) ↔ ∀x(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B))) |
| 20 | 19 | albii 1566 |
. . . . 5
⊢ (∀t(t ∈ 1c
→ (t ∈ 𝒫1A ↔ t ∈ 𝒫1B)) ↔ ∀t∀x(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B))) |
| 21 | | alcom 1737 |
. . . . 5
⊢ (∀t∀x(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B)) ↔ ∀x∀t(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B))) |
| 22 | 20, 21 | bitri 240 |
. . . 4
⊢ (∀t(t ∈ 1c
→ (t ∈ 𝒫1A ↔ t ∈ 𝒫1B)) ↔ ∀x∀t(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B))) |
| 23 | 15, 22 | bitri 240 |
. . 3
⊢ (∀t ∈ 1c (t ∈
𝒫1A ↔ t ∈
𝒫1B) ↔ ∀x∀t(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B))) |
| 24 | 14, 23 | bitri 240 |
. 2
⊢
(𝒫1A =
𝒫1B ↔ ∀x∀t(t = {x} →
(t ∈
𝒫1A ↔ t ∈
𝒫1B))) |
| 25 | | dfcleq 2347 |
. 2
⊢ (A = B ↔
∀x(x ∈ A ↔
x ∈
B)) |
| 26 | 10, 24, 25 | 3bitr4i 268 |
1
⊢
(𝒫1A =
𝒫1B ↔ A = B) |