Description: A contradiction implies anything. Inference associated with pm2.21i and pm2.24i . (Contributed by NM, 27-Feb-2008)
Ref | Expression | ||
---|---|---|---|
Hypotheses | pm2.24ii.1 | |- ph |
|
pm2.24ii.2 | |- -. ph |
||
Assertion | pm2.24ii | |- ps |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pm2.24ii.1 | |- ph |
|
2 | pm2.24ii.2 | |- -. ph |
|
3 | 2 | pm2.21i | |- ( ph -> ps ) |
4 | 1 3 | ax-mp | |- ps |