Description: Define the singleton function. See brsingle for its value. (Contributed by Scott Fenton, 4-Apr-2014)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-singleton |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | csingle | ||
| 1 | cvv | ||
| 2 | 1 1 | cxp | |
| 3 | cep | ||
| 4 | 1 3 | ctxp | |
| 5 | cid | ||
| 6 | 5 1 | ctxp | |
| 7 | 4 6 | csymdif | |
| 8 | 7 | crn | |
| 9 | 2 8 | cdif | |
| 10 | 0 9 | wceq |