Description: Negative of both sides of 'less than or equal to'. (Contributed by NM, 12-Sep-1999) (Proof shortened by Mario Carneiro, 27-May-2016)
Ref | Expression | ||
---|---|---|---|
Assertion | leneg | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0re | |
|
2 | lesub2 | |
|
3 | 1 2 | mp3an3 | |
4 | df-neg | |
|
5 | df-neg | |
|
6 | 4 5 | breq12i | |
7 | 3 6 | bitr4di | |