| Step |
Hyp |
Ref |
Expression |
| 1 |
|
maxidln1.1 |
|- H = ( 2nd ` R ) |
| 2 |
|
maxidln1.2 |
|- U = ( GId ` H ) |
| 3 |
|
eqid |
|- ( 1st ` R ) = ( 1st ` R ) |
| 4 |
|
eqid |
|- ran ( 1st ` R ) = ran ( 1st ` R ) |
| 5 |
3 4
|
maxidlnr |
|- ( ( R e. RingOps /\ M e. ( MaxIdl ` R ) ) -> M =/= ran ( 1st ` R ) ) |
| 6 |
|
maxidlidl |
|- ( ( R e. RingOps /\ M e. ( MaxIdl ` R ) ) -> M e. ( Idl ` R ) ) |
| 7 |
3 1 4 2
|
1idl |
|- ( ( R e. RingOps /\ M e. ( Idl ` R ) ) -> ( U e. M <-> M = ran ( 1st ` R ) ) ) |
| 8 |
7
|
necon3bbid |
|- ( ( R e. RingOps /\ M e. ( Idl ` R ) ) -> ( -. U e. M <-> M =/= ran ( 1st ` R ) ) ) |
| 9 |
6 8
|
syldan |
|- ( ( R e. RingOps /\ M e. ( MaxIdl ` R ) ) -> ( -. U e. M <-> M =/= ran ( 1st ` R ) ) ) |
| 10 |
5 9
|
mpbird |
|- ( ( R e. RingOps /\ M e. ( MaxIdl ` R ) ) -> -. U e. M ) |