Description: De Morgan's law for join in an ortholattice. ( chdmj1 analog.) (Contributed by NM, 6-Nov-2011)
Ref | Expression | ||
---|---|---|---|
Hypotheses | oldmm1.b | |
|
oldmm1.j | |
||
oldmm1.m | |
||
oldmm1.o | |
||
Assertion | oldmj1 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | oldmm1.b | |
|
2 | oldmm1.j | |
|
3 | oldmm1.m | |
|
4 | oldmm1.o | |
|
5 | 1 2 3 4 | oldmm4 | |
6 | 5 | fveq2d | |
7 | olop | |
|
8 | 7 | 3ad2ant1 | |
9 | ollat | |
|
10 | 9 | 3ad2ant1 | |
11 | 1 4 | opoccl | |
12 | 7 11 | sylan | |
13 | 12 | 3adant3 | |
14 | 1 4 | opoccl | |
15 | 7 14 | sylan | |
16 | 15 | 3adant2 | |
17 | 1 3 | latmcl | |
18 | 10 13 16 17 | syl3anc | |
19 | 1 4 | opococ | |
20 | 8 18 19 | syl2anc | |
21 | 6 20 | eqtr3d | |