Proof of Theorem sbabel
| Step | Hyp | Ref
| Expression |
| 1 | | sbex 998 |
. . 3
⊢ ([y /
x]∃v(v = {z∣φ}
∧ v ∈ A) ↔ ∃v[y / x](v = {z∣φ}
∧ v ∈ A)) |
| 2 | | sban 889 |
. . . . 5
⊢ ([y /
x](v =
{z∣φ} ∧ v ∈ A)
↔ ([y / x]v = {z∣φ}
∧ [y / x]v ∈
A)) |
| 3 | | ax-17 925 |
. . . . . . . . . 10
⊢ (w
∈ v → ∀x w ∈
v) |
| 4 | | sbabel.1 |
. . . . . . . . . 10
⊢ (w
∈ A → ∀x w ∈
A) |
| 5 | 3, 4 | hbel 1172 |
. . . . . . . . 9
⊢ (v
∈ A → ∀x v ∈
A) |
| 6 | 5 | sbf 870 |
. . . . . . . 8
⊢ ([y /
x]v
∈ A ↔ v ∈ A) |
| 7 | 6 | anbi2i 367 |
. . . . . . 7
⊢ (([y /
x]v =
{z∣φ} ∧ [y / x]v ∈ A)
↔ ([y / x]v = {z∣φ}
∧ v ∈ A)) |
| 8 | 7 | bicomi 150 |
. . . . . 6
⊢ (([y /
x]v =
{z∣φ} ∧ v ∈ A)
↔ ([y / x]v = {z∣φ}
∧ [y / x]v ∈
A)) |
| 9 | | sbal 997 |
. . . . . . . . 9
⊢ ([y /
x]∀z(z ∈
v ↔ φ) ↔ ∀z[y / x](z ∈
v ↔ φ)) |
| 10 | | sbbi 890 |
. . . . . . . . . . 11
⊢ ([y /
x](z
∈ v ↔ φ) ↔ ([y / x]z ∈ v
↔ [y / x]φ)) |
| 11 | | ax-17 925 |
. . . . . . . . . . . . . 14
⊢ (z
∈ v → ∀x z ∈
v) |
| 12 | 11 | sbf 870 |
. . . . . . . . . . . . 13
⊢ ([y /
x]z
∈ v ↔ z ∈ v) |
| 13 | 12 | bibi1i 461 |
. . . . . . . . . . . 12
⊢ (([y /
x]z
∈ v ↔ [y / x]φ) ↔ (z ∈ v
↔ [y / x]φ)) |
| 14 | 13 | bicomi 150 |
. . . . . . . . . . 11
⊢ ((z
∈ v ↔ [y / x]φ) ↔ ([y / x]z ∈ v
↔ [y / x]φ)) |
| 15 | 10, 14 | bitr4 154 |
. . . . . . . . . 10
⊢ ([y /
x](z
∈ v ↔ φ) ↔ (z ∈ v
↔ [y / x]φ)) |
| 16 | 15 | bial 695 |
. . . . . . . . 9
⊢ (∀z[y / x](z ∈
v ↔ φ) ↔ ∀z(z ∈
v ↔ [y / x]φ)) |
| 17 | 9, 16 | bitr 151 |
. . . . . . . 8
⊢ ([y /
x]∀z(z ∈
v ↔ φ) ↔ ∀z(z ∈
v ↔ [y / x]φ)) |
| 18 | | cleqab 1174 |
. . . . . . . . 9
⊢ (v =
{z∣φ} ↔ ∀z(z ∈
v ↔ φ)) |
| 19 | 18 | bisb 855 |
. . . . . . . 8
⊢ ([y /
x]v =
{z∣φ} ↔ [y / x]∀z(z ∈
v ↔ φ)) |
| 20 | | cleqab 1174 |
. . . . . . . 8
⊢ (v =
{z∣[y / x]φ} ↔ ∀z(z ∈
v ↔ [y / x]φ)) |
| 21 | 17, 19, 20 | 3bitr4 158 |
. . . . . . 7
⊢ ([y /
x]v =
{z∣φ} ↔ v = {z∣[y /
x]φ}) |
| 22 | 21 | anbi1i 368 |
. . . . . 6
⊢ (([y /
x]v =
{z∣φ} ∧ v ∈ A)
↔ (v = {z∣[y /
x]φ} ∧ v ∈ A)) |
| 23 | 8, 22 | bitr3 153 |
. . . . 5
⊢ (([y /
x]v =
{z∣φ} ∧ [y / x]v ∈ A)
↔ (v = {z∣[y /
x]φ} ∧ v ∈ A)) |
| 24 | 2, 23 | bitr 151 |
. . . 4
⊢ ([y /
x](v =
{z∣φ} ∧ v ∈ A)
↔ (v = {z∣[y /
x]φ} ∧ v ∈ A)) |
| 25 | 24 | biex 733 |
. . 3
⊢ (∃v[y / x](v = {z∣φ}
∧ v ∈ A) ↔ ∃v(v = {z∣[y /
x]φ} ∧ v ∈ A)) |
| 26 | 1, 25 | bitr 151 |
. 2
⊢ ([y /
x]∃v(v = {z∣φ}
∧ v ∈ A) ↔ ∃v(v = {z∣[y /
x]φ} ∧ v ∈ A)) |
| 27 | | df-clel 1099 |
. . 3
⊢ ({z∣φ}
∈ A ↔ ∃v(v = {z∣φ}
∧ v ∈ A)) |
| 28 | 27 | bisb 855 |
. 2
⊢ ([y /
x]{z∣φ}
∈ A ↔ [y / x]∃v(v = {z∣φ}
∧ v ∈ A)) |
| 29 | | df-clel 1099 |
. 2
⊢ ({z∣[y /
x]φ} ∈ A ↔ ∃v(v = {z∣[y /
x]φ} ∧ v ∈ A)) |
| 30 | 26, 28, 29 | 3bitr4 158 |
1
⊢ ([y /
x]{z∣φ}
∈ A ↔ {z∣[y /
x]φ} ∈ A) |