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. |