Description: Obsolete proof of opprbas as of 6-Nov-2024. Addition operation of an opposite ring. (Contributed by Mario Carneiro, 1-Dec-2014) (New usage is discouraged.) (Proof modification is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | opprbas.1 | |- O = ( oppR ` R ) |
|
| oppradd.2 | |- .+ = ( +g ` R ) |
||
| Assertion | oppraddOLD | |- .+ = ( +g ` O ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | opprbas.1 | |- O = ( oppR ` R ) |
|
| 2 | oppradd.2 | |- .+ = ( +g ` R ) |
|
| 3 | df-plusg | |- +g = Slot 2 |
|
| 4 | 2nn | |- 2 e. NN |
|
| 5 | 2lt3 | |- 2 < 3 |
|
| 6 | 1 3 4 5 | opprlemOLD | |- ( +g ` R ) = ( +g ` O ) |
| 7 | 2 6 | eqtri | |- .+ = ( +g ` O ) |