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| Mirrors > Home > NFE Home > Th. List > df-fal | Unicode version | ||
Description: Definition of  , a contradiction. is a constant false.
(Contributed by Anthony Hart, 22-Oct-2010.) |
| Ref | Expression |
|---|---|
| df-fal |
      |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | wfal 1317 |
. 2
 | |
| 2 | wtru 1316 |
. . 3
| |
| 3 | 2 | wn 3 |
. 2
|
| 4 | 1, 3 | wb 176 |
1
|
| Colors of variables: wff setvar class |
| This definition is referenced by: fal 1322 nottru 1348 |
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