Description: An opposite ring is a ring. (Contributed by Mario Carneiro, 1-Dec-2014) (Revised by Mario Carneiro, 30-Aug-2015)
Ref | Expression | ||
---|---|---|---|
Hypothesis | opprbas.1 | |
|
Assertion | opprring | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | opprbas.1 | |
|
2 | eqid | |
|
3 | 1 2 | opprbas | |
4 | 3 | a1i | |
5 | eqid | |
|
6 | 1 5 | oppradd | |
7 | 6 | a1i | |
8 | eqidd | |
|
9 | ringgrp | |
|
10 | 3 6 | grpprop | |
11 | 9 10 | sylib | |
12 | eqid | |
|
13 | eqid | |
|
14 | 2 12 1 13 | opprmul | |
15 | 2 12 | ringcl | |
16 | 15 | 3com23 | |
17 | 14 16 | eqeltrid | |
18 | simpl | |
|
19 | simpr3 | |
|
20 | simpr2 | |
|
21 | simpr1 | |
|
22 | 2 12 | ringass | |
23 | 18 19 20 21 22 | syl13anc | |
24 | 23 | eqcomd | |
25 | 14 | oveq1i | |
26 | 2 12 1 13 | opprmul | |
27 | 25 26 | eqtri | |
28 | 2 12 1 13 | opprmul | |
29 | 28 | oveq2i | |
30 | 2 12 1 13 | opprmul | |
31 | 29 30 | eqtri | |
32 | 24 27 31 | 3eqtr4g | |
33 | 2 5 12 | ringdir | |
34 | 18 20 19 21 33 | syl13anc | |
35 | 2 12 1 13 | opprmul | |
36 | 2 12 1 13 | opprmul | |
37 | 14 36 | oveq12i | |
38 | 34 35 37 | 3eqtr4g | |
39 | 2 5 12 | ringdi | |
40 | 18 19 21 20 39 | syl13anc | |
41 | 2 12 1 13 | opprmul | |
42 | 36 28 | oveq12i | |
43 | 40 41 42 | 3eqtr4g | |
44 | eqid | |
|
45 | 2 44 | ringidcl | |
46 | 2 12 1 13 | opprmul | |
47 | 2 12 44 | ringridm | |
48 | 46 47 | eqtrid | |
49 | 2 12 1 13 | opprmul | |
50 | 2 12 44 | ringlidm | |
51 | 49 50 | eqtrid | |
52 | 4 7 8 11 17 32 38 43 45 48 51 | isringd | |