| Step |
Hyp |
Ref |
Expression |
| 1 |
|
3atnelvol.j |
|- .\/ = ( join ` K ) |
| 2 |
|
3atnelvol.a |
|- A = ( Atoms ` K ) |
| 3 |
|
3atnelvol.v |
|- V = ( LVols ` K ) |
| 4 |
|
hllat |
|- ( K e. HL -> K e. Lat ) |
| 5 |
4
|
adantr |
|- ( ( K e. HL /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> K e. Lat ) |
| 6 |
|
eqid |
|- ( Base ` K ) = ( Base ` K ) |
| 7 |
6 1 2
|
hlatjcl |
|- ( ( K e. HL /\ P e. A /\ Q e. A ) -> ( P .\/ Q ) e. ( Base ` K ) ) |
| 8 |
7
|
3adant3r3 |
|- ( ( K e. HL /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> ( P .\/ Q ) e. ( Base ` K ) ) |
| 9 |
|
simpr3 |
|- ( ( K e. HL /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> R e. A ) |
| 10 |
6 2
|
atbase |
|- ( R e. A -> R e. ( Base ` K ) ) |
| 11 |
9 10
|
syl |
|- ( ( K e. HL /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> R e. ( Base ` K ) ) |
| 12 |
6 1
|
latjcl |
|- ( ( K e. Lat /\ ( P .\/ Q ) e. ( Base ` K ) /\ R e. ( Base ` K ) ) -> ( ( P .\/ Q ) .\/ R ) e. ( Base ` K ) ) |
| 13 |
5 8 11 12
|
syl3anc |
|- ( ( K e. HL /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> ( ( P .\/ Q ) .\/ R ) e. ( Base ` K ) ) |
| 14 |
|
eqid |
|- ( le ` K ) = ( le ` K ) |
| 15 |
6 14
|
latref |
|- ( ( K e. Lat /\ ( ( P .\/ Q ) .\/ R ) e. ( Base ` K ) ) -> ( ( P .\/ Q ) .\/ R ) ( le ` K ) ( ( P .\/ Q ) .\/ R ) ) |
| 16 |
5 13 15
|
syl2anc |
|- ( ( K e. HL /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> ( ( P .\/ Q ) .\/ R ) ( le ` K ) ( ( P .\/ Q ) .\/ R ) ) |
| 17 |
14 1 2 3
|
lvolnle3at |
|- ( ( ( K e. HL /\ ( ( P .\/ Q ) .\/ R ) e. V ) /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> -. ( ( P .\/ Q ) .\/ R ) ( le ` K ) ( ( P .\/ Q ) .\/ R ) ) |
| 18 |
17
|
an32s |
|- ( ( ( K e. HL /\ ( P e. A /\ Q e. A /\ R e. A ) ) /\ ( ( P .\/ Q ) .\/ R ) e. V ) -> -. ( ( P .\/ Q ) .\/ R ) ( le ` K ) ( ( P .\/ Q ) .\/ R ) ) |
| 19 |
18
|
ex |
|- ( ( K e. HL /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> ( ( ( P .\/ Q ) .\/ R ) e. V -> -. ( ( P .\/ Q ) .\/ R ) ( le ` K ) ( ( P .\/ Q ) .\/ R ) ) ) |
| 20 |
16 19
|
mt2d |
|- ( ( K e. HL /\ ( P e. A /\ Q e. A /\ R e. A ) ) -> -. ( ( P .\/ Q ) .\/ R ) e. V ) |