Description: Definition of the truth value "false", or "falsum", denoted by F. . See also df-tru . (Contributed by Anthony Hart, 22-Oct-2010)
Ref | Expression | ||
---|---|---|---|
Assertion | df-fal | |- ( F. <-> -. T. ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | wfal | |- F. |
|
1 | wtru | |- T. |
|
2 | 1 | wn | |- -. T. |
3 | 0 2 | wb | |- ( F. <-> -. T. ) |