New Foundations Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > NFE Home > Th. List > pm2.65i | Unicode version |
Description: Inference rule for proof by contradiction. (Contributed by NM, 18-May-1994.) (Proof shortened by Wolf Lammen, 11-Sep-2013.) |
Ref | Expression |
---|---|
pm2.65i.1 | |
pm2.65i.2 |
Ref | Expression |
---|---|
pm2.65i |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pm2.65i.2 | . . 3 | |
2 | 1 | con2i 112 | . 2 |
3 | pm2.65i.1 | . . 3 | |
4 | 3 | con3i 127 | . 2 |
5 | 2, 4 | pm2.61i 156 | 1 |
Colors of variables: wff setvar class |
Syntax hints: wn 3 wi 4 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 |
This theorem is referenced by: mto 167 mt2 170 noel 3554 |
Copyright terms: Public domain | W3C validator |