Description: Define the class of all symmetric sets. It is used only by df-symrels .
Note the similarity of Definitions df-refs , df-syms and df-trs , cf. the comment of dfrefrels2 . (Contributed by Peter Mazsa, 19-Jul-2019)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-syms |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | csyms | ||
| 1 | vx | ||
| 2 | 1 | cv | |
| 3 | 2 | cdm | |
| 4 | 2 | crn | |
| 5 | 3 4 | cxp | |
| 6 | 2 5 | cin | |
| 7 | 6 | ccnv | |
| 8 | cssr | ||
| 9 | 7 6 8 | wbr | |
| 10 | 9 1 | cab | |
| 11 | 0 10 | wceq |