| Step |
Hyp |
Ref |
Expression |
| 1 |
|
llnexch.l |
|- .<_ = ( le ` K ) |
| 2 |
|
llnexch.j |
|- .\/ = ( join ` K ) |
| 3 |
|
llnexch.m |
|- ./\ = ( meet ` K ) |
| 4 |
|
llnexch.a |
|- A = ( Atoms ` K ) |
| 5 |
|
llnexch.n |
|- N = ( LLines ` K ) |
| 6 |
1 2 3 4 5
|
llnexchb2 |
|- ( ( K e. HL /\ ( X e. N /\ Y e. N /\ Z e. N ) /\ ( ( X ./\ Y ) e. A /\ X =/= Z ) ) -> ( ( X ./\ Y ) .<_ Z <-> ( X ./\ Y ) = ( X ./\ Z ) ) ) |
| 7 |
|
hllat |
|- ( K e. HL -> K e. Lat ) |
| 8 |
7
|
3ad2ant1 |
|- ( ( K e. HL /\ ( X e. N /\ Y e. N /\ Z e. N ) /\ ( ( X ./\ Y ) e. A /\ X =/= Z ) ) -> K e. Lat ) |
| 9 |
|
simp21 |
|- ( ( K e. HL /\ ( X e. N /\ Y e. N /\ Z e. N ) /\ ( ( X ./\ Y ) e. A /\ X =/= Z ) ) -> X e. N ) |
| 10 |
|
eqid |
|- ( Base ` K ) = ( Base ` K ) |
| 11 |
10 5
|
llnbase |
|- ( X e. N -> X e. ( Base ` K ) ) |
| 12 |
9 11
|
syl |
|- ( ( K e. HL /\ ( X e. N /\ Y e. N /\ Z e. N ) /\ ( ( X ./\ Y ) e. A /\ X =/= Z ) ) -> X e. ( Base ` K ) ) |
| 13 |
|
simp22 |
|- ( ( K e. HL /\ ( X e. N /\ Y e. N /\ Z e. N ) /\ ( ( X ./\ Y ) e. A /\ X =/= Z ) ) -> Y e. N ) |
| 14 |
10 5
|
llnbase |
|- ( Y e. N -> Y e. ( Base ` K ) ) |
| 15 |
13 14
|
syl |
|- ( ( K e. HL /\ ( X e. N /\ Y e. N /\ Z e. N ) /\ ( ( X ./\ Y ) e. A /\ X =/= Z ) ) -> Y e. ( Base ` K ) ) |
| 16 |
10 1 3
|
latmle2 |
|- ( ( K e. Lat /\ X e. ( Base ` K ) /\ Y e. ( Base ` K ) ) -> ( X ./\ Y ) .<_ Y ) |
| 17 |
8 12 15 16
|
syl3anc |
|- ( ( K e. HL /\ ( X e. N /\ Y e. N /\ Z e. N ) /\ ( ( X ./\ Y ) e. A /\ X =/= Z ) ) -> ( X ./\ Y ) .<_ Y ) |
| 18 |
|
breq1 |
|- ( ( X ./\ Y ) = ( X ./\ Z ) -> ( ( X ./\ Y ) .<_ Y <-> ( X ./\ Z ) .<_ Y ) ) |
| 19 |
17 18
|
syl5ibcom |
|- ( ( K e. HL /\ ( X e. N /\ Y e. N /\ Z e. N ) /\ ( ( X ./\ Y ) e. A /\ X =/= Z ) ) -> ( ( X ./\ Y ) = ( X ./\ Z ) -> ( X ./\ Z ) .<_ Y ) ) |
| 20 |
6 19
|
sylbid |
|- ( ( K e. HL /\ ( X e. N /\ Y e. N /\ Z e. N ) /\ ( ( X ./\ Y ) e. A /\ X =/= Z ) ) -> ( ( X ./\ Y ) .<_ Z -> ( X ./\ Z ) .<_ Y ) ) |