Proof of Theorem frds
Step | Hyp | Ref
| Expression |
1 | | frds.4 |
. . 3
⊢ (φ → R Fr A) |
2 | | dfrab2 3531 |
. . . . 5
⊢ {x ∈ A ∣ ψ} = ({x
∣ ψ}
∩ A) |
3 | | df-rab 2624 |
. . . . 5
⊢ {x ∈ A ∣ ψ} = {x
∣ (x
∈ A ∧ ψ)} |
4 | 2, 3 | eqtr3i 2375 |
. . . 4
⊢ ({x ∣ ψ} ∩ A) = {x ∣ (x ∈ A ∧ ψ)} |
5 | | frds.1 |
. . . . 5
⊢ {x ∣ ψ} ∈
V |
6 | | brex 4690 |
. . . . . . 7
⊢ (R Fr A → (R
∈ V ∧
A ∈
V)) |
7 | 1, 6 | syl 15 |
. . . . . 6
⊢ (φ → (R ∈ V ∧ A ∈ V)) |
8 | 7 | simprd 449 |
. . . . 5
⊢ (φ → A ∈
V) |
9 | | inexg 4101 |
. . . . 5
⊢ (({x ∣ ψ} ∈ V
∧ A ∈ V) → ({x
∣ ψ}
∩ A) ∈ V) |
10 | 5, 8, 9 | sylancr 644 |
. . . 4
⊢ (φ → ({x ∣ ψ} ∩ A) ∈
V) |
11 | 4, 10 | syl5eqelr 2438 |
. . 3
⊢ (φ → {x ∣ (x ∈ A ∧ ψ)} ∈
V) |
12 | | ssab2 3351 |
. . . 4
⊢ {x ∣ (x ∈ A ∧ ψ)} ⊆
A |
13 | 12 | a1i 10 |
. . 3
⊢ (φ → {x ∣ (x ∈ A ∧ ψ)} ⊆
A) |
14 | | frds.5 |
. . . . 5
⊢ (φ → ∃x ∈ A ψ) |
15 | | df-rex 2621 |
. . . . 5
⊢ (∃x ∈ A ψ ↔ ∃x(x ∈ A ∧ ψ)) |
16 | 14, 15 | sylib 188 |
. . . 4
⊢ (φ → ∃x(x ∈ A ∧ ψ)) |
17 | | abn0 3569 |
. . . 4
⊢ ({x ∣ (x ∈ A ∧ ψ)} ≠ ∅
↔ ∃x(x ∈ A ∧ ψ)) |
18 | 16, 17 | sylibr 203 |
. . 3
⊢ (φ → {x ∣ (x ∈ A ∧ ψ)} ≠ ∅) |
19 | 1, 11, 13, 18 | frd 5923 |
. 2
⊢ (φ → ∃y ∈ {x ∣ (x ∈ A ∧ ψ)}∀z ∈ {x ∣ (x ∈ A ∧ ψ)}
(zRy →
z = y)) |
20 | | eleq1 2413 |
. . . . . 6
⊢ (x = y →
(x ∈
A ↔ y ∈ A)) |
21 | | frds.2 |
. . . . . 6
⊢ (x = y →
(ψ ↔ χ)) |
22 | 20, 21 | anbi12d 691 |
. . . . 5
⊢ (x = y →
((x ∈
A ∧ ψ) ↔ (y ∈ A ∧ χ))) |
23 | 22 | rexab 3000 |
. . . 4
⊢ (∃y ∈ {x ∣ (x ∈ A ∧ ψ)}∀z ∈ A ((θ ∧
zRy) →
z = y)
↔ ∃y((y ∈ A ∧ χ) ∧ ∀z ∈ A ((θ
∧ zRy) → z =
y))) |
24 | | anass 630 |
. . . . 5
⊢ (((y ∈ A ∧ χ) ∧ ∀z ∈ A ((θ ∧
zRy) →
z = y))
↔ (y ∈ A ∧ (χ ∧ ∀z ∈ A ((θ
∧ zRy) → z =
y)))) |
25 | 24 | exbii 1582 |
. . . 4
⊢ (∃y((y ∈ A ∧ χ) ∧ ∀z ∈ A ((θ ∧
zRy) →
z = y))
↔ ∃y(y ∈ A ∧ (χ ∧ ∀z ∈ A ((θ
∧ zRy) → z =
y)))) |
26 | 23, 25 | bitri 240 |
. . 3
⊢ (∃y ∈ {x ∣ (x ∈ A ∧ ψ)}∀z ∈ A ((θ ∧
zRy) →
z = y)
↔ ∃y(y ∈ A ∧ (χ ∧ ∀z ∈ A ((θ
∧ zRy) → z =
y)))) |
27 | | impexp 433 |
. . . . . . 7
⊢ (((z ∈ A ∧ θ) → (zRy → z =
y)) ↔ (z ∈ A → (θ → (zRy → z =
y)))) |
28 | | impexp 433 |
. . . . . . . 8
⊢ (((θ ∧
zRy) →
z = y)
↔ (θ → (zRy → z =
y))) |
29 | 28 | imbi2i 303 |
. . . . . . 7
⊢ ((z ∈ A → ((θ ∧
zRy) →
z = y))
↔ (z ∈ A →
(θ → (zRy → z =
y)))) |
30 | 27, 29 | bitr4i 243 |
. . . . . 6
⊢ (((z ∈ A ∧ θ) → (zRy → z =
y)) ↔ (z ∈ A → ((θ ∧
zRy) →
z = y))) |
31 | 30 | albii 1566 |
. . . . 5
⊢ (∀z((z ∈ A ∧ θ) → (zRy → z =
y)) ↔ ∀z(z ∈ A → ((θ ∧
zRy) →
z = y))) |
32 | | eleq1 2413 |
. . . . . . 7
⊢ (x = z →
(x ∈
A ↔ z ∈ A)) |
33 | | frds.3 |
. . . . . . 7
⊢ (x = z →
(ψ ↔ θ)) |
34 | 32, 33 | anbi12d 691 |
. . . . . 6
⊢ (x = z →
((x ∈
A ∧ ψ) ↔ (z ∈ A ∧ θ))) |
35 | 34 | ralab 2998 |
. . . . 5
⊢ (∀z ∈ {x ∣ (x ∈ A ∧ ψ)}
(zRy →
z = y)
↔ ∀z((z ∈ A ∧ θ)
→ (zRy →
z = y))) |
36 | | df-ral 2620 |
. . . . 5
⊢ (∀z ∈ A ((θ ∧
zRy) →
z = y)
↔ ∀z(z ∈ A →
((θ ∧ zRy) →
z = y))) |
37 | 31, 35, 36 | 3bitr4i 268 |
. . . 4
⊢ (∀z ∈ {x ∣ (x ∈ A ∧ ψ)}
(zRy →
z = y)
↔ ∀z ∈ A ((θ
∧ zRy) → z =
y)) |
38 | 37 | rexbii 2640 |
. . 3
⊢ (∃y ∈ {x ∣ (x ∈ A ∧ ψ)}∀z ∈ {x ∣ (x ∈ A ∧ ψ)}
(zRy →
z = y)
↔ ∃y ∈ {x ∣ (x ∈ A ∧ ψ)}∀z ∈ A ((θ ∧
zRy) →
z = y)) |
39 | | df-rex 2621 |
. . 3
⊢ (∃y ∈ A (χ ∧ ∀z ∈ A ((θ ∧
zRy) →
z = y))
↔ ∃y(y ∈ A ∧ (χ ∧ ∀z ∈ A ((θ
∧ zRy) → z =
y)))) |
40 | 26, 38, 39 | 3bitr4i 268 |
. 2
⊢ (∃y ∈ {x ∣ (x ∈ A ∧ ψ)}∀z ∈ {x ∣ (x ∈ A ∧ ψ)}
(zRy →
z = y)
↔ ∃y ∈ A (χ ∧ ∀z ∈ A ((θ
∧ zRy) → z =
y))) |
41 | 19, 40 | sylib 188 |
1
⊢ (φ → ∃y ∈ A (χ ∧ ∀z ∈ A ((θ ∧
zRy) →
z = y))) |