Proof of Theorem exmidpweq
| Step | Hyp | Ref
| Expression |
| 1 | | exmid01 4231 |
. . . . . . . 8
⊢
(EXMID ↔ ∀𝑥(𝑥 ⊆ {∅} → (𝑥 = ∅ ∨ 𝑥 = {∅}))) |
| 2 | 1 | biimpi 120 |
. . . . . . 7
⊢
(EXMID → ∀𝑥(𝑥 ⊆ {∅} → (𝑥 = ∅ ∨ 𝑥 = {∅}))) |
| 3 | 2 | 19.21bi 1572 |
. . . . . 6
⊢
(EXMID → (𝑥 ⊆ {∅} → (𝑥 = ∅ ∨ 𝑥 = {∅}))) |
| 4 | | df1o2 6487 |
. . . . . . . . 9
⊢
1o = {∅} |
| 5 | 4 | pweqi 3609 |
. . . . . . . 8
⊢ 𝒫
1o = 𝒫 {∅} |
| 6 | 5 | eleq2i 2263 |
. . . . . . 7
⊢ (𝑥 ∈ 𝒫 1o
↔ 𝑥 ∈ 𝒫
{∅}) |
| 7 | | velpw 3612 |
. . . . . . 7
⊢ (𝑥 ∈ 𝒫 {∅}
↔ 𝑥 ⊆
{∅}) |
| 8 | 6, 7 | bitri 184 |
. . . . . 6
⊢ (𝑥 ∈ 𝒫 1o
↔ 𝑥 ⊆
{∅}) |
| 9 | | vex 2766 |
. . . . . . 7
⊢ 𝑥 ∈ V |
| 10 | 9 | elpr 3643 |
. . . . . 6
⊢ (𝑥 ∈ {∅, {∅}}
↔ (𝑥 = ∅ ∨
𝑥 =
{∅})) |
| 11 | 3, 8, 10 | 3imtr4g 205 |
. . . . 5
⊢
(EXMID → (𝑥 ∈ 𝒫 1o → 𝑥 ∈ {∅,
{∅}})) |
| 12 | 11 | ssrdv 3189 |
. . . 4
⊢
(EXMID → 𝒫 1o ⊆ {∅,
{∅}}) |
| 13 | | pwpw0ss 3834 |
. . . . . 6
⊢ {∅,
{∅}} ⊆ 𝒫 {∅} |
| 14 | 13, 5 | sseqtrri 3218 |
. . . . 5
⊢ {∅,
{∅}} ⊆ 𝒫 1o |
| 15 | 14 | a1i 9 |
. . . 4
⊢
(EXMID → {∅, {∅}} ⊆ 𝒫
1o) |
| 16 | 12, 15 | eqssd 3200 |
. . 3
⊢
(EXMID → 𝒫 1o = {∅,
{∅}}) |
| 17 | | df2o2 6489 |
. . 3
⊢
2o = {∅, {∅}} |
| 18 | 16, 17 | eqtr4di 2247 |
. 2
⊢
(EXMID → 𝒫 1o =
2o) |
| 19 | | simpr 110 |
. . . . . . . . 9
⊢
((𝒫 1o = 2o ∧ 𝑥 ⊆ {∅}) → 𝑥 ⊆ {∅}) |
| 20 | 19, 7 | sylibr 134 |
. . . . . . . 8
⊢
((𝒫 1o = 2o ∧ 𝑥 ⊆ {∅}) → 𝑥 ∈ 𝒫 {∅}) |
| 21 | 20, 5 | eleqtrrdi 2290 |
. . . . . . 7
⊢
((𝒫 1o = 2o ∧ 𝑥 ⊆ {∅}) → 𝑥 ∈ 𝒫
1o) |
| 22 | | simpl 109 |
. . . . . . . 8
⊢
((𝒫 1o = 2o ∧ 𝑥 ⊆ {∅}) → 𝒫
1o = 2o) |
| 23 | 22, 17 | eqtrdi 2245 |
. . . . . . 7
⊢
((𝒫 1o = 2o ∧ 𝑥 ⊆ {∅}) → 𝒫
1o = {∅, {∅}}) |
| 24 | 21, 23 | eleqtrd 2275 |
. . . . . 6
⊢
((𝒫 1o = 2o ∧ 𝑥 ⊆ {∅}) → 𝑥 ∈ {∅,
{∅}}) |
| 25 | 24, 10 | sylib 122 |
. . . . 5
⊢
((𝒫 1o = 2o ∧ 𝑥 ⊆ {∅}) → (𝑥 = ∅ ∨ 𝑥 = {∅})) |
| 26 | 25 | ex 115 |
. . . 4
⊢
(𝒫 1o = 2o → (𝑥 ⊆ {∅} → (𝑥 = ∅ ∨ 𝑥 = {∅}))) |
| 27 | 26 | alrimiv 1888 |
. . 3
⊢
(𝒫 1o = 2o → ∀𝑥(𝑥 ⊆ {∅} → (𝑥 = ∅ ∨ 𝑥 = {∅}))) |
| 28 | 27, 1 | sylibr 134 |
. 2
⊢
(𝒫 1o = 2o →
EXMID) |
| 29 | 18, 28 | impbii 126 |
1
⊢
(EXMID ↔ 𝒫 1o =
2o) |