| Step |
Hyp |
Ref |
Expression |
| 1 |
|
oppggic.o |
|- O = ( oppG ` G ) |
| 2 |
|
oppgcntz.z |
|- Z = ( Cntz ` G ) |
| 3 |
|
eqcom |
|- ( ( x ( +g ` G ) y ) = ( y ( +g ` G ) x ) <-> ( y ( +g ` G ) x ) = ( x ( +g ` G ) y ) ) |
| 4 |
|
eqid |
|- ( +g ` G ) = ( +g ` G ) |
| 5 |
|
eqid |
|- ( +g ` O ) = ( +g ` O ) |
| 6 |
4 1 5
|
oppgplus |
|- ( x ( +g ` O ) y ) = ( y ( +g ` G ) x ) |
| 7 |
4 1 5
|
oppgplus |
|- ( y ( +g ` O ) x ) = ( x ( +g ` G ) y ) |
| 8 |
6 7
|
eqeq12i |
|- ( ( x ( +g ` O ) y ) = ( y ( +g ` O ) x ) <-> ( y ( +g ` G ) x ) = ( x ( +g ` G ) y ) ) |
| 9 |
3 8
|
bitr4i |
|- ( ( x ( +g ` G ) y ) = ( y ( +g ` G ) x ) <-> ( x ( +g ` O ) y ) = ( y ( +g ` O ) x ) ) |
| 10 |
9
|
ralbii |
|- ( A. y e. A ( x ( +g ` G ) y ) = ( y ( +g ` G ) x ) <-> A. y e. A ( x ( +g ` O ) y ) = ( y ( +g ` O ) x ) ) |
| 11 |
10
|
anbi2i |
|- ( ( x e. ( Base ` G ) /\ A. y e. A ( x ( +g ` G ) y ) = ( y ( +g ` G ) x ) ) <-> ( x e. ( Base ` G ) /\ A. y e. A ( x ( +g ` O ) y ) = ( y ( +g ` O ) x ) ) ) |
| 12 |
11
|
anbi2i |
|- ( ( A C_ ( Base ` G ) /\ ( x e. ( Base ` G ) /\ A. y e. A ( x ( +g ` G ) y ) = ( y ( +g ` G ) x ) ) ) <-> ( A C_ ( Base ` G ) /\ ( x e. ( Base ` G ) /\ A. y e. A ( x ( +g ` O ) y ) = ( y ( +g ` O ) x ) ) ) ) |
| 13 |
|
eqid |
|- ( Base ` G ) = ( Base ` G ) |
| 14 |
13 2
|
cntzrcl |
|- ( x e. ( Z ` A ) -> ( G e. _V /\ A C_ ( Base ` G ) ) ) |
| 15 |
14
|
simprd |
|- ( x e. ( Z ` A ) -> A C_ ( Base ` G ) ) |
| 16 |
13 4 2
|
elcntz |
|- ( A C_ ( Base ` G ) -> ( x e. ( Z ` A ) <-> ( x e. ( Base ` G ) /\ A. y e. A ( x ( +g ` G ) y ) = ( y ( +g ` G ) x ) ) ) ) |
| 17 |
15 16
|
biadanii |
|- ( x e. ( Z ` A ) <-> ( A C_ ( Base ` G ) /\ ( x e. ( Base ` G ) /\ A. y e. A ( x ( +g ` G ) y ) = ( y ( +g ` G ) x ) ) ) ) |
| 18 |
1 13
|
oppgbas |
|- ( Base ` G ) = ( Base ` O ) |
| 19 |
|
eqid |
|- ( Cntz ` O ) = ( Cntz ` O ) |
| 20 |
18 19
|
cntzrcl |
|- ( x e. ( ( Cntz ` O ) ` A ) -> ( O e. _V /\ A C_ ( Base ` G ) ) ) |
| 21 |
20
|
simprd |
|- ( x e. ( ( Cntz ` O ) ` A ) -> A C_ ( Base ` G ) ) |
| 22 |
18 5 19
|
elcntz |
|- ( A C_ ( Base ` G ) -> ( x e. ( ( Cntz ` O ) ` A ) <-> ( x e. ( Base ` G ) /\ A. y e. A ( x ( +g ` O ) y ) = ( y ( +g ` O ) x ) ) ) ) |
| 23 |
21 22
|
biadanii |
|- ( x e. ( ( Cntz ` O ) ` A ) <-> ( A C_ ( Base ` G ) /\ ( x e. ( Base ` G ) /\ A. y e. A ( x ( +g ` O ) y ) = ( y ( +g ` O ) x ) ) ) ) |
| 24 |
12 17 23
|
3bitr4i |
|- ( x e. ( Z ` A ) <-> x e. ( ( Cntz ` O ) ` A ) ) |
| 25 |
24
|
eqriv |
|- ( Z ` A ) = ( ( Cntz ` O ) ` A ) |