Description: Closure law for negative. (Contributed by NM, 26-Nov-1994)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | negidi.1 | |- A e. CC |
|
| Assertion | negcli | |- -u A e. CC |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | negidi.1 | |- A e. CC |
|
| 2 | negcl | |- ( A e. CC -> -u A e. CC ) |
|
| 3 | 1 2 | ax-mp | |- -u A e. CC |