Description: Hilbert lattice contraposition law. (Contributed by NM, 24-Jun-2004) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypotheses | ch0le.1 | |
|
chjcl.2 | |
||
Assertion | chcon2i | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ch0le.1 | |
|
2 | chjcl.2 | |
|
3 | 1 2 | chsscon2i | |
4 | 2 1 | chsscon1i | |
5 | 3 4 | anbi12i | |
6 | eqss | |
|
7 | eqss | |
|
8 | 5 6 7 | 3bitr4i | |