| Step |
Hyp |
Ref |
Expression |
| 1 |
|
zcn |
|- ( x e. ZZ -> x e. CC ) |
| 2 |
|
zaddcl |
|- ( ( x e. ZZ /\ y e. ZZ ) -> ( x + y ) e. ZZ ) |
| 3 |
|
znegcl |
|- ( x e. ZZ -> -u x e. ZZ ) |
| 4 |
|
1z |
|- 1 e. ZZ |
| 5 |
1 2 3 4
|
cnsubglem |
|- ZZ e. ( SubGrp ` CCfld ) |
| 6 |
|
eqid |
|- ( .g ` CCfld ) = ( .g ` CCfld ) |
| 7 |
|
df-zring |
|- ZZring = ( CCfld |`s ZZ ) |
| 8 |
|
eqid |
|- ( .g ` ZZring ) = ( .g ` ZZring ) |
| 9 |
6 7 8
|
subgmulg |
|- ( ( ZZ e. ( SubGrp ` CCfld ) /\ A e. ZZ /\ B e. ZZ ) -> ( A ( .g ` CCfld ) B ) = ( A ( .g ` ZZring ) B ) ) |
| 10 |
5 9
|
mp3an1 |
|- ( ( A e. ZZ /\ B e. ZZ ) -> ( A ( .g ` CCfld ) B ) = ( A ( .g ` ZZring ) B ) ) |
| 11 |
|
simpr |
|- ( ( A e. ZZ /\ B e. ZZ ) -> B e. ZZ ) |
| 12 |
11
|
zcnd |
|- ( ( A e. ZZ /\ B e. ZZ ) -> B e. CC ) |
| 13 |
|
cnfldmulg |
|- ( ( A e. ZZ /\ B e. CC ) -> ( A ( .g ` CCfld ) B ) = ( A x. B ) ) |
| 14 |
12 13
|
syldan |
|- ( ( A e. ZZ /\ B e. ZZ ) -> ( A ( .g ` CCfld ) B ) = ( A x. B ) ) |
| 15 |
10 14
|
eqtr3d |
|- ( ( A e. ZZ /\ B e. ZZ ) -> ( A ( .g ` ZZring ) B ) = ( A x. B ) ) |