Proof of Theorem funimaexg
| Step | Hyp | Ref
| Expression |
| 1 | | imaeq2 2603 |
. . . 4
⊢ (w =
B → (A “ w) =
(A “ B)) |
| 2 | 1 | eleq1d 1155 |
. . 3
⊢ (w =
B → ((A “ w)
∈ V ↔ (A “ B) ∈ V)) |
| 3 | 2 | imbi2d 464 |
. 2
⊢ (w =
B → ((Fun A → (A
“ w) ∈ V) ↔ (Fun
A → (A “ B)
∈ V))) |
| 4 | | dffun5 2677 |
. . . 4
⊢ (Fun A
↔ (Rel A ∧ ∀x∃z∀y(〈x,
y〉 ∈ A → y =
z))) |
| 5 | 4 | pm3.27bd 263 |
. . 3
⊢ (Fun A
→ ∀x∃z∀y(〈x,
y〉 ∈ A → y =
z)) |
| 6 | | ax-17 925 |
. . . . 5
⊢ (〈x, y〉
∈ A → ∀z〈x,
y〉 ∈ A) |
| 7 | 6 | zfrep2 1475 |
. . . 4
⊢ (∀x∃z∀y(〈x,
y〉 ∈ A → y =
z) → ∃z∀y(y ∈
z ↔ ∃x(x ∈
w ∧ 〈x, y〉
∈ A))) |
| 8 | | isset 1351 |
. . . . 5
⊢ ((A
“ w) ∈ V ↔
∃z z = (A “
w)) |
| 9 | | dfima3 2605 |
. . . . . . . 8
⊢ (A
“ w) = {y∣∃x(x ∈
w ∧ 〈x, y〉
∈ A)} |
| 10 | 9 | cleq2i 1111 |
. . . . . . 7
⊢ (z =
(A “ w) ↔ z =
{y∣∃x(x ∈
w ∧ 〈x, y〉
∈ A)}) |
| 11 | | cleqab 1174 |
. . . . . . 7
⊢ (z =
{y∣∃x(x ∈
w ∧ 〈x, y〉
∈ A)} ↔ ∀y(y ∈
z ↔ ∃x(x ∈
w ∧ 〈x, y〉
∈ A))) |
| 12 | 10, 11 | bitr 151 |
. . . . . 6
⊢ (z =
(A “ w) ↔ ∀y(y ∈
z ↔ ∃x(x ∈
w ∧ 〈x, y〉
∈ A))) |
| 13 | 12 | biex 733 |
. . . . 5
⊢ (∃z z = (A “ w)
↔ ∃z∀y(y ∈
z ↔ ∃x(x ∈
w ∧ 〈x, y〉
∈ A))) |
| 14 | 8, 13 | bitr 151 |
. . . 4
⊢ ((A
“ w) ∈ V ↔
∃z∀y(y ∈
z ↔ ∃x(x ∈
w ∧ 〈x, y〉
∈ A))) |
| 15 | 7, 14 | sylibr 175 |
. . 3
⊢ (∀x∃z∀y(〈x,
y〉 ∈ A → y =
z) → (A “ w)
∈ V) |
| 16 | 5, 15 | syl 12 |
. 2
⊢ (Fun A
→ (A “ w) ∈ V) |
| 17 | 3, 16 | vtoclg 1383 |
1
⊢ (B
∈ C → (Fun A → (A
“ B) ∈ V)) |