Proof of Theorem 2reu5lem2
Step | Hyp | Ref
| Expression |
1 | | df-rmo 2623 |
. . 3
⊢ (∃*y ∈ B φ ↔ ∃*y(y ∈ B ∧ φ)) |
2 | 1 | ralbii 2639 |
. 2
⊢ (∀x ∈ A ∃*y ∈ B φ ↔ ∀x ∈ A ∃*y(y ∈ B ∧ φ)) |
3 | | df-ral 2620 |
. . 3
⊢ (∀x ∈ A ∃*y(y ∈ B ∧ φ) ↔ ∀x(x ∈ A → ∃*y(y ∈ B ∧ φ))) |
4 | | moanimv 2262 |
. . . . . 6
⊢ (∃*y(x ∈ A ∧ (y ∈ B ∧ φ)) ↔ (x ∈ A → ∃*y(y ∈ B ∧ φ))) |
5 | 4 | bicomi 193 |
. . . . 5
⊢ ((x ∈ A → ∃*y(y ∈ B ∧ φ)) ↔ ∃*y(x ∈ A ∧ (y ∈ B ∧ φ))) |
6 | | 3anass 938 |
. . . . . . 7
⊢ ((x ∈ A ∧ y ∈ B ∧ φ) ↔ (x ∈ A ∧ (y ∈ B ∧ φ))) |
7 | 6 | bicomi 193 |
. . . . . 6
⊢ ((x ∈ A ∧ (y ∈ B ∧ φ)) ↔ (x ∈ A ∧ y ∈ B ∧ φ)) |
8 | 7 | mobii 2240 |
. . . . 5
⊢ (∃*y(x ∈ A ∧ (y ∈ B ∧ φ)) ↔ ∃*y(x ∈ A ∧ y ∈ B ∧ φ)) |
9 | 5, 8 | bitri 240 |
. . . 4
⊢ ((x ∈ A → ∃*y(y ∈ B ∧ φ)) ↔ ∃*y(x ∈ A ∧ y ∈ B ∧ φ)) |
10 | 9 | albii 1566 |
. . 3
⊢ (∀x(x ∈ A → ∃*y(y ∈ B ∧ φ)) ↔ ∀x∃*y(x ∈ A ∧ y ∈ B ∧ φ)) |
11 | 3, 10 | bitri 240 |
. 2
⊢ (∀x ∈ A ∃*y(y ∈ B ∧ φ) ↔ ∀x∃*y(x ∈ A ∧ y ∈ B ∧ φ)) |
12 | 2, 11 | bitri 240 |
1
⊢ (∀x ∈ A ∃*y ∈ B φ ↔ ∀x∃*y(x ∈ A ∧ y ∈ B ∧ φ)) |