Description: Hilbert lattice contraposition law. (Contributed by NM, 15-Jun-2006) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypotheses | ch0le.1 | ||
chjcl.2 | |||
Assertion | chcon1i |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ch0le.1 | ||
2 | chjcl.2 | ||
3 | 2 1 | chcon2i | |
4 | eqcom | ||
5 | eqcom | ||
6 | 3 4 5 | 3bitr4i |