Description: De Morgan's law for meet in an ortholattice. ( chdmm2 analog.) (Contributed by NM, 6-Nov-2011)
Ref | Expression | ||
---|---|---|---|
Hypotheses | oldmm1.b | |
|
oldmm1.j | |
||
oldmm1.m | |
||
oldmm1.o | |
||
Assertion | oldmm2 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | oldmm1.b | |
|
2 | oldmm1.j | |
|
3 | oldmm1.m | |
|
4 | oldmm1.o | |
|
5 | olop | |
|
6 | 1 4 | opoccl | |
7 | 5 6 | sylan | |
8 | 7 | 3adant3 | |
9 | 1 2 3 4 | oldmm1 | |
10 | 8 9 | syld3an2 | |
11 | 1 4 | opococ | |
12 | 5 11 | sylan | |
13 | 12 | 3adant3 | |
14 | 13 | oveq1d | |
15 | 10 14 | eqtrd | |