| Step |
Hyp |
Ref |
Expression |
| 1 |
|
elscottrankss |
|- ( ( A e. Scott B /\ C e. B ) -> ( rank ` A ) C_ ( rank ` C ) ) |
| 2 |
1
|
3adant3 |
|- ( ( A e. Scott B /\ C e. B /\ -. C e. Scott B ) -> ( rank ` A ) C_ ( rank ` C ) ) |
| 3 |
|
scottrankeqel |
|- ( ( A e. Scott B /\ C e. B /\ ( rank ` C ) = ( rank ` A ) ) -> C e. Scott B ) |
| 4 |
3
|
3expia |
|- ( ( A e. Scott B /\ C e. B ) -> ( ( rank ` C ) = ( rank ` A ) -> C e. Scott B ) ) |
| 5 |
4
|
necon3bd |
|- ( ( A e. Scott B /\ C e. B ) -> ( -. C e. Scott B -> ( rank ` C ) =/= ( rank ` A ) ) ) |
| 6 |
5
|
3impia |
|- ( ( A e. Scott B /\ C e. B /\ -. C e. Scott B ) -> ( rank ` C ) =/= ( rank ` A ) ) |
| 7 |
6
|
necomd |
|- ( ( A e. Scott B /\ C e. B /\ -. C e. Scott B ) -> ( rank ` A ) =/= ( rank ` C ) ) |
| 8 |
|
rankon |
|- ( rank ` A ) e. On |
| 9 |
|
rankon |
|- ( rank ` C ) e. On |
| 10 |
|
onelpss |
|- ( ( ( rank ` A ) e. On /\ ( rank ` C ) e. On ) -> ( ( rank ` A ) e. ( rank ` C ) <-> ( ( rank ` A ) C_ ( rank ` C ) /\ ( rank ` A ) =/= ( rank ` C ) ) ) ) |
| 11 |
8 9 10
|
mp2an |
|- ( ( rank ` A ) e. ( rank ` C ) <-> ( ( rank ` A ) C_ ( rank ` C ) /\ ( rank ` A ) =/= ( rank ` C ) ) ) |
| 12 |
2 7 11
|
sylanbrc |
|- ( ( A e. Scott B /\ C e. B /\ -. C e. Scott B ) -> ( rank ` A ) e. ( rank ` C ) ) |