Description: The negative function in an opposite ring. (Contributed by Mario Carneiro, 5-Dec-2014) (Revised by Mario Carneiro, 2-Oct-2015)
Ref | Expression | ||
---|---|---|---|
Hypotheses | opprbas.1 | |
|
opprneg.2 | |
||
Assertion | opprneg | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | opprbas.1 | |
|
2 | opprneg.2 | |
|
3 | eqid | |
|
4 | eqid | |
|
5 | eqid | |
|
6 | 3 4 5 2 | grpinvfval | |
7 | 1 3 | opprbas | |
8 | 1 4 | oppradd | |
9 | 1 5 | oppr0 | |
10 | eqid | |
|
11 | 7 8 9 10 | grpinvfval | |
12 | 6 11 | eqtr4i | |