Description: Ortholattice meet is associative. (This can also be proved for lattices with a longer proof.) ( inass analog.) (Contributed by NM, 7-Nov-2011) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypotheses | olmass.b | |
|
olmass.m | |
||
Assertion | latmassOLD | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | olmass.b | |
|
2 | olmass.m | |
|
3 | simpl | |
|
4 | ollat | |
|
5 | 4 | adantr | |
6 | olop | |
|
7 | 6 | adantr | |
8 | simpr1 | |
|
9 | eqid | |
|
10 | 1 9 | opoccl | |
11 | 7 8 10 | syl2anc | |
12 | simpr2 | |
|
13 | 1 9 | opoccl | |
14 | 7 12 13 | syl2anc | |
15 | eqid | |
|
16 | 1 15 | latjcl | |
17 | 5 11 14 16 | syl3anc | |
18 | simpr3 | |
|
19 | 1 15 2 9 | oldmj3 | |
20 | 3 17 18 19 | syl3anc | |
21 | 1 9 | opoccl | |
22 | 7 18 21 | syl2anc | |
23 | 1 15 | latjass | |
24 | 5 11 14 22 23 | syl13anc | |
25 | 24 | fveq2d | |
26 | 1 15 2 9 | oldmj4 | |
27 | 26 | 3adant3r3 | |
28 | 27 | oveq1d | |
29 | 20 25 28 | 3eqtr3rd | |
30 | 1 15 | latjcl | |
31 | 5 14 22 30 | syl3anc | |
32 | 1 15 2 9 | oldmj2 | |
33 | 3 8 31 32 | syl3anc | |
34 | 1 15 2 9 | oldmj4 | |
35 | 34 | 3adant3r1 | |
36 | 35 | oveq2d | |
37 | 29 33 36 | 3eqtrd | |