| Step |
Hyp |
Ref |
Expression |
| 1 |
|
isso2i.1 |
|- ( ( x e. A /\ y e. A ) -> ( x R y <-> -. ( x = y \/ y R x ) ) ) |
| 2 |
|
isso2i.2 |
|- ( ( x e. A /\ y e. A /\ z e. A ) -> ( ( x R y /\ y R z ) -> x R z ) ) |
| 3 |
|
equid |
|- x = x |
| 4 |
3
|
orci |
|- ( x = x \/ x R x ) |
| 5 |
|
nfv |
|- F/ y ( ( x e. A /\ x e. A ) -> ( ( x = x \/ x R x ) <-> -. x R x ) ) |
| 6 |
|
eleq1w |
|- ( y = x -> ( y e. A <-> x e. A ) ) |
| 7 |
6
|
anbi2d |
|- ( y = x -> ( ( x e. A /\ y e. A ) <-> ( x e. A /\ x e. A ) ) ) |
| 8 |
|
equequ2 |
|- ( y = x -> ( x = y <-> x = x ) ) |
| 9 |
|
breq1 |
|- ( y = x -> ( y R x <-> x R x ) ) |
| 10 |
8 9
|
orbi12d |
|- ( y = x -> ( ( x = y \/ y R x ) <-> ( x = x \/ x R x ) ) ) |
| 11 |
|
breq2 |
|- ( y = x -> ( x R y <-> x R x ) ) |
| 12 |
11
|
notbid |
|- ( y = x -> ( -. x R y <-> -. x R x ) ) |
| 13 |
10 12
|
bibi12d |
|- ( y = x -> ( ( ( x = y \/ y R x ) <-> -. x R y ) <-> ( ( x = x \/ x R x ) <-> -. x R x ) ) ) |
| 14 |
7 13
|
imbi12d |
|- ( y = x -> ( ( ( x e. A /\ y e. A ) -> ( ( x = y \/ y R x ) <-> -. x R y ) ) <-> ( ( x e. A /\ x e. A ) -> ( ( x = x \/ x R x ) <-> -. x R x ) ) ) ) |
| 15 |
1
|
con2bid |
|- ( ( x e. A /\ y e. A ) -> ( ( x = y \/ y R x ) <-> -. x R y ) ) |
| 16 |
5 14 15
|
chvarfv |
|- ( ( x e. A /\ x e. A ) -> ( ( x = x \/ x R x ) <-> -. x R x ) ) |
| 17 |
4 16
|
mpbii |
|- ( ( x e. A /\ x e. A ) -> -. x R x ) |
| 18 |
17
|
anidms |
|- ( x e. A -> -. x R x ) |
| 19 |
15
|
biimprd |
|- ( ( x e. A /\ y e. A ) -> ( -. x R y -> ( x = y \/ y R x ) ) ) |
| 20 |
19
|
orrd |
|- ( ( x e. A /\ y e. A ) -> ( x R y \/ ( x = y \/ y R x ) ) ) |
| 21 |
|
3orass |
|- ( ( x R y \/ x = y \/ y R x ) <-> ( x R y \/ ( x = y \/ y R x ) ) ) |
| 22 |
20 21
|
sylibr |
|- ( ( x e. A /\ y e. A ) -> ( x R y \/ x = y \/ y R x ) ) |
| 23 |
18 2 22
|
issoi |
|- R Or A |