Description: Hilbert lattice contraposition law for strict ordering. (Contributed by NM, 12-Jun-2004) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | chpsscon3 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | chsscon3 | |
|
2 | chsscon3 | |
|
3 | 2 | ancoms | |
4 | 3 | notbid | |
5 | 1 4 | anbi12d | |
6 | dfpss3 | |
|
7 | dfpss3 | |
|
8 | 5 6 7 | 3bitr4g | |