Description: The involution function of a constructed star ring. (Contributed by Mario Carneiro, 20-Jun-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | srngstr.r | ||
| Assertion | srnginvl | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | srngstr.r | ||
| 2 | 1 | srngstr | |
| 3 | starvid | ||
| 4 | ssun2 | ||
| 5 | 4 1 | sseqtrri | |
| 6 | 2 3 5 | strfv |