Description: Miscellaneous inference relating falsehoods. (Contributed by NM, 31-Mar-1994)
Ref | Expression | ||
---|---|---|---|
Hypothesis | niabn.1 | |
|
Assertion | niabn | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | niabn.1 | |
|
2 | simpr | |
|
3 | 1 | pm2.24i | |
4 | 2 3 | pm5.21ni | |