Proof of Theorem sbcel12g
| Step | Hyp | Ref
| Expression |
| 1 | | elisset 1813 |
. . 3
⊢ (A
∈ D → A ∈ V) |
| 2 | | sbcexg 1971 |
. . . . 5
⊢ (A
∈ V → ([A / x]∃z(z = B ⋀ z
∈ C) ↔ ∃z[A / x](z = B ⋀ z
∈ C))) |
| 3 | | df-clel 1470 |
. . . . . 6
⊢ (B
∈ C ↔ ∃z(z = B ⋀ z
∈ C)) |
| 4 | 3 | sbcbii 1974 |
. . . . 5
⊢ (A
∈ V → ([A / x]B ∈
C ↔ [A / x]∃z(z = B ⋀ z
∈ C))) |
| 5 | | dfcleq 1468 |
. . . . . . . . . . 11
⊢ (z =
B ↔ ∀y(y ∈
z ↔ y ∈ B)) |
| 6 | 5 | sbcbii 1974 |
. . . . . . . . . 10
⊢ (A
∈ V → ([A / x]z = B ↔ [A /
x]∀y(y ∈
z ↔ y ∈ B))) |
| 7 | | sbcalg 1970 |
. . . . . . . . . 10
⊢ (A
∈ V → ([A / x]∀y(y ∈
z ↔ y ∈ B)
↔ ∀y[A / x](y ∈ z
↔ y ∈ B))) |
| 8 | | sbcbidig 1969 |
. . . . . . . . . . . 12
⊢ (A
∈ V → ([A / x](y ∈
z ↔ y ∈ B)
↔ ([A / x]y ∈
z ↔ [A / x]y ∈ B))) |
| 9 | | ax-17 969 |
. . . . . . . . . . . . . 14
⊢ (y
∈ z → ∀x y ∈
z) |
| 10 | 9 | sbcgf 1982 |
. . . . . . . . . . . . 13
⊢ (A
∈ V → ([A / x]y ∈
z ↔ y ∈ z)) |
| 11 | 10 | bibi1d 618 |
. . . . . . . . . . . 12
⊢ (A
∈ V → (([A / x]y ∈
z ↔ [A / x]y ∈ B)
↔ (y ∈ z ↔ [A /
x]y
∈ B))) |
| 12 | 8, 11 | bitrd 527 |
. . . . . . . . . . 11
⊢ (A
∈ V → ([A / x](y ∈
z ↔ y ∈ B)
↔ (y ∈ z ↔ [A /
x]y
∈ B))) |
| 13 | 12 | albidv 1276 |
. . . . . . . . . 10
⊢ (A
∈ V → (∀y[A / x](y ∈ z
↔ y ∈ B) ↔ ∀y(y ∈
z ↔ [A / x]y ∈ B))) |
| 14 | 6, 7, 13 | 3bitrd 543 |
. . . . . . . . 9
⊢ (A
∈ V → ([A / x]z = B ↔ ∀y(y ∈
z ↔ [A / x]y ∈ B))) |
| 15 | | abeq2 1565 |
. . . . . . . . 9
⊢ (z =
{y∣[A / x]y ∈ B}
↔ ∀y(y ∈ z
↔ [A / x]y ∈
B)) |
| 16 | 14, 15 | syl6rbbr 538 |
. . . . . . . 8
⊢ (A
∈ V → (z = {y∣[A /
x]y
∈ B} ↔ [A / x]z = B)) |
| 17 | | eleq1 1531 |
. . . . . . . . . . . 12
⊢ (y =
z → (y ∈ C
↔ z ∈ C)) |
| 18 | 17 | sbcbidv 1973 |
. . . . . . . . . . 11
⊢ ((y =
z ⋀ A ∈ V) → ([A / x]y ∈ C
↔ [A / x]z ∈
C)) |
| 19 | 18 | expcom 374 |
. . . . . . . . . 10
⊢ (A
∈ V → (y = z → ([A /
x]y
∈ C ↔ [A / x]z ∈ C))) |
| 20 | 19 | 19.21aiv 1284 |
. . . . . . . . 9
⊢ (A
∈ V → ∀y(y = z →
([A / x]y ∈
C ↔ [A / x]z ∈ C))) |
| 21 | | visset 1809 |
. . . . . . . . . 10
⊢ z
∈ V |
| 22 | | elabgt 1891 |
. . . . . . . . . 10
⊢ ((z
∈ V ⋀ ∀y(y = z →
([A / x]y ∈
C ↔ [A / x]z ∈ C)))
→ (z ∈ {y∣[A /
x]y
∈ C} ↔ [A / x]z ∈ C)) |
| 23 | 21, 22 | mpan 694 |
. . . . . . . . 9
⊢ (∀y(y = z → ([A /
x]y
∈ C ↔ [A / x]z ∈ C))
→ (z ∈ {y∣[A /
x]y
∈ C} ↔ [A / x]z ∈ C)) |
| 24 | 20, 23 | syl 10 |
. . . . . . . 8
⊢ (A
∈ V → (z ∈ {y∣[A /
x]y
∈ C} ↔ [A / x]z ∈ C)) |
| 25 | 16, 24 | anbi12d 627 |
. . . . . . 7
⊢ (A
∈ V → ((z = {y∣[A /
x]y
∈ B} ⋀ z ∈ {y∣[A /
x]y
∈ C}) ↔ ([A / x]z = B ⋀
[A / x]z ∈
C))) |
| 26 | | sbcang 1967 |
. . . . . . 7
⊢ (A
∈ V → ([A / x](z = B ⋀ z
∈ C) ↔ ([A / x]z = B ⋀
[A / x]z ∈
C))) |
| 27 | 25, 26 | bitr4d 530 |
. . . . . 6
⊢ (A
∈ V → ((z = {y∣[A /
x]y
∈ B} ⋀ z ∈ {y∣[A /
x]y
∈ C}) ↔ [A / x](z = B ⋀
z ∈ C))) |
| 28 | 27 | exbidv 1277 |
. . . . 5
⊢ (A
∈ V → (∃z(z = {y∣[A /
x]y
∈ B} ⋀ z ∈ {y∣[A /
x]y
∈ C}) ↔ ∃z[A / x](z = B ⋀ z
∈ C))) |
| 29 | 2, 4, 28 | 3bitr4d 549 |
. . . 4
⊢ (A
∈ V → ([A / x]B ∈
C ↔ ∃z(z = {y∣[A /
x]y
∈ B} ⋀ z ∈ {y∣[A /
x]y
∈ C}))) |
| 30 | | df-clel 1470 |
. . . 4
⊢ ({y∣[A /
x]y
∈ B} ∈ {y∣[A /
x]y
∈ C} ↔ ∃z(z = {y∣[A /
x]y
∈ B} ⋀ z ∈ {y∣[A /
x]y
∈ C})) |
| 31 | 29, 30 | syl6bbr 537 |
. . 3
⊢ (A
∈ V → ([A / x]B ∈
C ↔ {y∣[A /
x]y
∈ B} ∈ {y∣[A /
x]y
∈ C})) |
| 32 | 1, 31 | syl 10 |
. 2
⊢ (A
∈ D → ([A / x]B ∈ C
↔ {y∣[A / x]y ∈ B}
∈ {y∣[A / x]y ∈ C})) |
| 33 | | df-csb 1998 |
. . 3
⊢ [A / x]B =
{y∣[A / x]y ∈ B} |
| 34 | | df-csb 1998 |
. . 3
⊢ [A / x]C =
{y∣[A / x]y ∈ C} |
| 35 | 33, 34 | eleq12i 1536 |
. 2
⊢ ([A / x]B
∈ [A / x]C
↔ {y∣[A / x]y ∈ B}
∈ {y∣[A / x]y ∈ C}) |
| 36 | 32, 35 | syl6bbr 537 |
1
⊢ (A
∈ D → ([A / x]B ∈ C
↔ [A / x]B
∈ [A / x]C)) |