| Step |
Hyp |
Ref |
Expression |
| 1 |
|
primefld1cl.1 |
|- .1. = ( 1r ` R ) |
| 2 |
|
issdrg |
|- ( s e. ( SubDRing ` R ) <-> ( R e. DivRing /\ s e. ( SubRing ` R ) /\ ( R |`s s ) e. DivRing ) ) |
| 3 |
2
|
simp2bi |
|- ( s e. ( SubDRing ` R ) -> s e. ( SubRing ` R ) ) |
| 4 |
3
|
a1i |
|- ( R e. DivRing -> ( s e. ( SubDRing ` R ) -> s e. ( SubRing ` R ) ) ) |
| 5 |
4
|
ssrdv |
|- ( R e. DivRing -> ( SubDRing ` R ) C_ ( SubRing ` R ) ) |
| 6 |
|
eqid |
|- ( Base ` R ) = ( Base ` R ) |
| 7 |
6
|
sdrgid |
|- ( R e. DivRing -> ( Base ` R ) e. ( SubDRing ` R ) ) |
| 8 |
7
|
ne0d |
|- ( R e. DivRing -> ( SubDRing ` R ) =/= (/) ) |
| 9 |
|
subrgint |
|- ( ( ( SubDRing ` R ) C_ ( SubRing ` R ) /\ ( SubDRing ` R ) =/= (/) ) -> |^| ( SubDRing ` R ) e. ( SubRing ` R ) ) |
| 10 |
5 8 9
|
syl2anc |
|- ( R e. DivRing -> |^| ( SubDRing ` R ) e. ( SubRing ` R ) ) |
| 11 |
1
|
subrg1cl |
|- ( |^| ( SubDRing ` R ) e. ( SubRing ` R ) -> .1. e. |^| ( SubDRing ` R ) ) |
| 12 |
10 11
|
syl |
|- ( R e. DivRing -> .1. e. |^| ( SubDRing ` R ) ) |