Description: There does not exist a set such that T. is not true. (Contributed by Anthony Hart, 13-Sep-2011)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | nexntru | |- -. E. x -. T. |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | tru | |- T. |
|
| 2 | 1 | notnoti | |- -. -. T. |
| 3 | 2 | nex | |- -. E. x -. T. |