Proof of Theorem fcnvres
| Step | Hyp | Ref
| Expression |
| 1 | | visset 1350 |
. . . . . . . . 9
⊢ y
∈ V |
| 2 | 1 | opelf 2762 |
. . . . . . . 8
⊢ ((F:A–→B
∧ 〈x, y〉 ∈ F) → (x
∈ A ∧ y ∈ B)) |
| 3 | 2 | pm3.26d 258 |
. . . . . . 7
⊢ ((F:A–→B
∧ 〈x, y〉 ∈ F) → x
∈ A) |
| 4 | 3 | exp 291 |
. . . . . 6
⊢ (F:A–→B
→ (〈x, y〉 ∈ F
→ x ∈ A)) |
| 5 | | pm4.71 481 |
. . . . . 6
⊢ ((〈x, y〉
∈ F → x ∈ A)
↔ (〈x, y〉 ∈ F
↔ (〈x, y〉 ∈ F
∧ x ∈ A))) |
| 6 | 4, 5 | sylib 173 |
. . . . 5
⊢ (F:A–→B
→ (〈x, y〉 ∈ F
↔ (〈x, y〉 ∈ F
∧ x ∈ A))) |
| 7 | | visset 1350 |
. . . . . . 7
⊢ x
∈ V |
| 8 | 1, 7 | opelcnv 2518 |
. . . . . 6
⊢ (〈y, x〉
∈ ◡(F ↾ A)
↔ 〈x, y〉 ∈ (F ↾ A)) |
| 9 | 1 | opelres 2579 |
. . . . . 6
⊢ (〈x, y〉
∈ (F ↾ A) ↔ (〈x, y〉
∈ F ∧ x ∈ A)) |
| 10 | 8, 9 | bitr 151 |
. . . . 5
⊢ (〈y, x〉
∈ ◡(F ↾ A)
↔ (〈x, y〉 ∈ F
∧ x ∈ A)) |
| 11 | 6, 10 | syl6bbr 416 |
. . . 4
⊢ (F:A–→B
→ (〈x, y〉 ∈ F
↔ 〈y, x〉 ∈ ◡(F
↾ A))) |
| 12 | 2 | pm3.27d 262 |
. . . . . . 7
⊢ ((F:A–→B
∧ 〈x, y〉 ∈ F) → y
∈ B) |
| 13 | 12 | exp 291 |
. . . . . 6
⊢ (F:A–→B
→ (〈x, y〉 ∈ F
→ y ∈ B)) |
| 14 | | pm4.71 481 |
. . . . . 6
⊢ ((〈x, y〉
∈ F → y ∈ B)
↔ (〈x, y〉 ∈ F
↔ (〈x, y〉 ∈ F
∧ y ∈ B))) |
| 15 | 13, 14 | sylib 173 |
. . . . 5
⊢ (F:A–→B
→ (〈x, y〉 ∈ F
↔ (〈x, y〉 ∈ F
∧ y ∈ B))) |
| 16 | 7 | opelres 2579 |
. . . . . 6
⊢ (〈y, x〉
∈ (◡F ↾ B)
↔ (〈y, x〉 ∈ ◡F ∧
y ∈ B)) |
| 17 | 1, 7 | opelcnv 2518 |
. . . . . . 7
⊢ (〈y, x〉
∈ ◡F ↔ 〈x, y〉
∈ F) |
| 18 | 17 | anbi1i 368 |
. . . . . 6
⊢ ((〈y, x〉
∈ ◡F ∧ y ∈
B) ↔ (〈x, y〉
∈ F ∧ y ∈ B)) |
| 19 | 16, 18 | bitr 151 |
. . . . 5
⊢ (〈y, x〉
∈ (◡F ↾ B)
↔ (〈x, y〉 ∈ F
∧ y ∈ B)) |
| 20 | 15, 19 | syl6bbr 416 |
. . . 4
⊢ (F:A–→B
→ (〈x, y〉 ∈ F
↔ 〈y, x〉 ∈ (◡F
↾ B))) |
| 21 | 11, 20 | bitr3d 408 |
. . 3
⊢ (F:A–→B
→ (〈y, x〉 ∈ ◡(F
↾ A) ↔ 〈y, x〉
∈ (◡F ↾ B))) |
| 22 | 21 | 19.21aivv 944 |
. 2
⊢ (F:A–→B
→ ∀y∀x(〈y,
x〉 ∈ ◡(F
↾ A) ↔ 〈y, x〉
∈ (◡F ↾ B))) |
| 23 | | relcnv 2624 |
. . 3
⊢ Rel ◡(F
↾ A) |
| 24 | | relres 2591 |
. . 3
⊢ Rel (◡F
↾ B) |
| 25 | | cleqrel 2483 |
. . 3
⊢ ((Rel ◡(F
↾ A) ∧ Rel (◡F
↾ B)) → (◡(F
↾ A) = (◡F
↾ B) ↔ ∀y∀x(〈y,
x〉 ∈ ◡(F
↾ A) ↔ 〈y, x〉
∈ (◡F ↾ B)))) |
| 26 | 23, 24, 25 | mp2an 520 |
. 2
⊢ (◡(F
↾ A) = (◡F
↾ B) ↔ ∀y∀x(〈y,
x〉 ∈ ◡(F
↾ A) ↔ 〈y, x〉
∈ (◡F ↾ B))) |
| 27 | 22, 26 | sylibr 175 |
1
⊢ (F:A–→B
→ ◡(F ↾ A) =
(◡F
↾ B)) |