Description: Being a subring is a symmetric property. (Contributed by Mario Carneiro, 6-Dec-2014)
Ref | Expression | ||
---|---|---|---|
Hypothesis | opprsubrg.o | |
|
Assertion | opprsubrg | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | opprsubrg.o | |
|
2 | subrgrcl | |
|
3 | subrgrcl | |
|
4 | 1 | opprringb | |
5 | 3 4 | sylibr | |
6 | 1 | opprsubg | |
7 | 6 | a1i | |
8 | 7 | eleq2d | |
9 | ralcom | |
|
10 | eqid | |
|
11 | eqid | |
|
12 | eqid | |
|
13 | 10 11 1 12 | opprmul | |
14 | 13 | eleq1i | |
15 | 14 | 2ralbii | |
16 | 9 15 | bitr4i | |
17 | 16 | a1i | |
18 | 8 17 | 3anbi13d | |
19 | eqid | |
|
20 | 10 19 11 | issubrg2 | |
21 | 1 10 | opprbas | |
22 | 1 19 | oppr1 | |
23 | 21 22 12 | issubrg2 | |
24 | 4 23 | sylbi | |
25 | 18 20 24 | 3bitr4d | |
26 | 2 5 25 | pm5.21nii | |
27 | 26 | eqriv | |