Proof of Theorem soeq1
| Step | Hyp | Ref
| Expression |
| 1 | | poeq1 2848 |
. . 3
⊢ (R = S →
(R Po A
↔ S Po A)) |
| 2 | | breq 2626 |
. . . . 5
⊢ (R = S →
(xRy ↔
xSy)) |
| 3 | | pm4.2d 171 |
. . . . 5
⊢ (R = S →
(x = y
↔ x = y)) |
| 4 | | breq 2626 |
. . . . 5
⊢ (R = S →
(yRx ↔
ySx)) |
| 5 | 2, 3, 4 | 3orbi123d 894 |
. . . 4
⊢ (R = S →
((xRy ⋁ x = y ⋁ yRx) ↔ (xSy ⋁ x = y ⋁ ySx))) |
| 6 | 5 | 2ralbidv 1683 |
. . 3
⊢ (R = S →
(∀x
∈ A ∀y ∈ A (xRy ⋁ x = y ⋁ yRx) ↔ ∀x ∈ A ∀y ∈ A (xSy ⋁ x = y ⋁ ySx))) |
| 7 | 1, 6 | anbi12d 630 |
. 2
⊢ (R = S →
((R Po A ⋀ ∀x ∈ A ∀y ∈ A (xRy ⋁ x = y ⋁ yRx)) ↔
(S Po A
⋀ ∀x ∈ A ∀y ∈ A (xSy ⋁ x = y ⋁ ySx)))) |
| 8 | | df-so 2856 |
. 2
⊢ (R Or A ↔
(R Po A
⋀ ∀x ∈ A ∀y ∈ A (xRy ⋁ x = y ⋁ yRx))) |
| 9 | | df-so 2856 |
. 2
⊢ (S Or A ↔
(S Po A
⋀ ∀x ∈ A ∀y ∈ A (xSy ⋁ x = y ⋁ ySx))) |
| 10 | 7, 8, 9 | 3bitr4g 557 |
1
⊢ (R = S →
(R Or A
↔ S Or A)) |