| Step |
Hyp |
Ref |
Expression |
| 1 |
|
brric |
|- ( R ~=r S <-> ( R RingIso S ) =/= (/) ) |
| 2 |
1
|
biimpi |
|- ( R ~=r S -> ( R RingIso S ) =/= (/) ) |
| 3 |
2
|
adantr |
|- ( ( R ~=r S /\ R e. NzRing ) -> ( R RingIso S ) =/= (/) ) |
| 4 |
|
rimrcl2 |
|- ( f e. ( R RingIso S ) -> S e. Ring ) |
| 5 |
4
|
adantl |
|- ( ( ( R ~=r S /\ R e. NzRing ) /\ f e. ( R RingIso S ) ) -> S e. Ring ) |
| 6 |
3 5
|
n0limd |
|- ( ( R ~=r S /\ R e. NzRing ) -> S e. Ring ) |
| 7 |
|
eqid |
|- ( 1r ` R ) = ( 1r ` R ) |
| 8 |
|
eqid |
|- ( 0g ` R ) = ( 0g ` R ) |
| 9 |
7 8
|
nzrnz |
|- ( R e. NzRing -> ( 1r ` R ) =/= ( 0g ` R ) ) |
| 10 |
9
|
ad2antlr |
|- ( ( ( R ~=r S /\ R e. NzRing ) /\ f e. ( R RingIso S ) ) -> ( 1r ` R ) =/= ( 0g ` R ) ) |
| 11 |
|
isrim0 |
|- ( f e. ( R RingIso S ) <-> ( f e. ( R RingHom S ) /\ `' f e. ( S RingHom R ) ) ) |
| 12 |
11
|
simprbi |
|- ( f e. ( R RingIso S ) -> `' f e. ( S RingHom R ) ) |
| 13 |
12
|
adantl |
|- ( ( ( R ~=r S /\ R e. NzRing ) /\ f e. ( R RingIso S ) ) -> `' f e. ( S RingHom R ) ) |
| 14 |
|
eqid |
|- ( 1r ` S ) = ( 1r ` S ) |
| 15 |
14 7
|
rhm1 |
|- ( `' f e. ( S RingHom R ) -> ( `' f ` ( 1r ` S ) ) = ( 1r ` R ) ) |
| 16 |
13 15
|
syl |
|- ( ( ( R ~=r S /\ R e. NzRing ) /\ f e. ( R RingIso S ) ) -> ( `' f ` ( 1r ` S ) ) = ( 1r ` R ) ) |
| 17 |
|
rhmghm |
|- ( `' f e. ( S RingHom R ) -> `' f e. ( S GrpHom R ) ) |
| 18 |
|
eqid |
|- ( 0g ` S ) = ( 0g ` S ) |
| 19 |
18 8
|
ghmid |
|- ( `' f e. ( S GrpHom R ) -> ( `' f ` ( 0g ` S ) ) = ( 0g ` R ) ) |
| 20 |
13 17 19
|
3syl |
|- ( ( ( R ~=r S /\ R e. NzRing ) /\ f e. ( R RingIso S ) ) -> ( `' f ` ( 0g ` S ) ) = ( 0g ` R ) ) |
| 21 |
10 16 20
|
3netr4d |
|- ( ( ( R ~=r S /\ R e. NzRing ) /\ f e. ( R RingIso S ) ) -> ( `' f ` ( 1r ` S ) ) =/= ( `' f ` ( 0g ` S ) ) ) |
| 22 |
|
fveq2 |
|- ( ( 1r ` S ) = ( 0g ` S ) -> ( `' f ` ( 1r ` S ) ) = ( `' f ` ( 0g ` S ) ) ) |
| 23 |
22
|
necon3i |
|- ( ( `' f ` ( 1r ` S ) ) =/= ( `' f ` ( 0g ` S ) ) -> ( 1r ` S ) =/= ( 0g ` S ) ) |
| 24 |
21 23
|
syl |
|- ( ( ( R ~=r S /\ R e. NzRing ) /\ f e. ( R RingIso S ) ) -> ( 1r ` S ) =/= ( 0g ` S ) ) |
| 25 |
3 24
|
n0limd |
|- ( ( R ~=r S /\ R e. NzRing ) -> ( 1r ` S ) =/= ( 0g ` S ) ) |
| 26 |
14 18
|
isnzr |
|- ( S e. NzRing <-> ( S e. Ring /\ ( 1r ` S ) =/= ( 0g ` S ) ) ) |
| 27 |
6 25 26
|
sylanbrc |
|- ( ( R ~=r S /\ R e. NzRing ) -> S e. NzRing ) |