| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 4at.l |  |-  .<_ = ( le ` K ) | 
						
							| 2 |  | 4at.j |  |-  .\/ = ( join ` K ) | 
						
							| 3 |  | 4at.a |  |-  A = ( Atoms ` K ) | 
						
							| 4 |  | simpl11 |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> K e. HL ) | 
						
							| 5 |  | simpl1 |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( K e. HL /\ P e. A /\ Q e. A ) ) | 
						
							| 6 |  | simpl21 |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> R e. A ) | 
						
							| 7 |  | simpl22 |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> S e. A ) | 
						
							| 8 |  | simpr |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) | 
						
							| 9 |  | eqid |  |-  ( LVols ` K ) = ( LVols ` K ) | 
						
							| 10 | 1 2 3 9 | lvoli2 |  |-  ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( ( P .\/ Q ) .\/ R ) .\/ S ) e. ( LVols ` K ) ) | 
						
							| 11 | 5 6 7 8 10 | syl121anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( ( P .\/ Q ) .\/ R ) .\/ S ) e. ( LVols ` K ) ) | 
						
							| 12 |  | simpl23 |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> T e. A ) | 
						
							| 13 |  | simpl3l |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> U e. A ) | 
						
							| 14 |  | simpl3r |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> V e. A ) | 
						
							| 15 | 1 2 3 9 | lvolnle3at |  |-  ( ( ( K e. HL /\ ( ( ( P .\/ Q ) .\/ R ) .\/ S ) e. ( LVols ` K ) ) /\ ( T e. A /\ U e. A /\ V e. A ) ) -> -. ( ( ( P .\/ Q ) .\/ R ) .\/ S ) .<_ ( ( T .\/ U ) .\/ V ) ) | 
						
							| 16 | 4 11 12 13 14 15 | syl23anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> -. ( ( ( P .\/ Q ) .\/ R ) .\/ S ) .<_ ( ( T .\/ U ) .\/ V ) ) | 
						
							| 17 | 4 | hllatd |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> K e. Lat ) | 
						
							| 18 |  | eqid |  |-  ( Base ` K ) = ( Base ` K ) | 
						
							| 19 | 18 2 3 | hlatjcl |  |-  ( ( K e. HL /\ P e. A /\ Q e. A ) -> ( P .\/ Q ) e. ( Base ` K ) ) | 
						
							| 20 | 5 19 | syl |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( P .\/ Q ) e. ( Base ` K ) ) | 
						
							| 21 | 18 2 3 | hlatjcl |  |-  ( ( K e. HL /\ R e. A /\ S e. A ) -> ( R .\/ S ) e. ( Base ` K ) ) | 
						
							| 22 | 4 6 7 21 | syl3anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( R .\/ S ) e. ( Base ` K ) ) | 
						
							| 23 | 18 2 3 | hlatjcl |  |-  ( ( K e. HL /\ T e. A /\ U e. A ) -> ( T .\/ U ) e. ( Base ` K ) ) | 
						
							| 24 | 4 12 13 23 | syl3anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( T .\/ U ) e. ( Base ` K ) ) | 
						
							| 25 | 18 3 | atbase |  |-  ( V e. A -> V e. ( Base ` K ) ) | 
						
							| 26 | 14 25 | syl |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> V e. ( Base ` K ) ) | 
						
							| 27 | 18 2 | latjcl |  |-  ( ( K e. Lat /\ ( T .\/ U ) e. ( Base ` K ) /\ V e. ( Base ` K ) ) -> ( ( T .\/ U ) .\/ V ) e. ( Base ` K ) ) | 
						
							| 28 | 17 24 26 27 | syl3anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( T .\/ U ) .\/ V ) e. ( Base ` K ) ) | 
						
							| 29 | 18 1 2 | latjle12 |  |-  ( ( K e. Lat /\ ( ( P .\/ Q ) e. ( Base ` K ) /\ ( R .\/ S ) e. ( Base ` K ) /\ ( ( T .\/ U ) .\/ V ) e. ( Base ` K ) ) ) -> ( ( ( P .\/ Q ) .<_ ( ( T .\/ U ) .\/ V ) /\ ( R .\/ S ) .<_ ( ( T .\/ U ) .\/ V ) ) <-> ( ( P .\/ Q ) .\/ ( R .\/ S ) ) .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 30 | 17 20 22 28 29 | syl13anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( ( P .\/ Q ) .<_ ( ( T .\/ U ) .\/ V ) /\ ( R .\/ S ) .<_ ( ( T .\/ U ) .\/ V ) ) <-> ( ( P .\/ Q ) .\/ ( R .\/ S ) ) .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 31 |  | simpl12 |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> P e. A ) | 
						
							| 32 | 18 3 | atbase |  |-  ( P e. A -> P e. ( Base ` K ) ) | 
						
							| 33 | 31 32 | syl |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> P e. ( Base ` K ) ) | 
						
							| 34 |  | simpl13 |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> Q e. A ) | 
						
							| 35 | 18 3 | atbase |  |-  ( Q e. A -> Q e. ( Base ` K ) ) | 
						
							| 36 | 34 35 | syl |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> Q e. ( Base ` K ) ) | 
						
							| 37 | 18 1 2 | latjle12 |  |-  ( ( K e. Lat /\ ( P e. ( Base ` K ) /\ Q e. ( Base ` K ) /\ ( ( T .\/ U ) .\/ V ) e. ( Base ` K ) ) ) -> ( ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) <-> ( P .\/ Q ) .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 38 | 17 33 36 28 37 | syl13anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) <-> ( P .\/ Q ) .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 39 | 18 3 | atbase |  |-  ( R e. A -> R e. ( Base ` K ) ) | 
						
							| 40 | 6 39 | syl |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> R e. ( Base ` K ) ) | 
						
							| 41 | 18 3 | atbase |  |-  ( S e. A -> S e. ( Base ` K ) ) | 
						
							| 42 | 7 41 | syl |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> S e. ( Base ` K ) ) | 
						
							| 43 | 18 1 2 | latjle12 |  |-  ( ( K e. Lat /\ ( R e. ( Base ` K ) /\ S e. ( Base ` K ) /\ ( ( T .\/ U ) .\/ V ) e. ( Base ` K ) ) ) -> ( ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) <-> ( R .\/ S ) .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 44 | 17 40 42 28 43 | syl13anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) <-> ( R .\/ S ) .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 45 | 38 44 | anbi12d |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) /\ ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) ) <-> ( ( P .\/ Q ) .<_ ( ( T .\/ U ) .\/ V ) /\ ( R .\/ S ) .<_ ( ( T .\/ U ) .\/ V ) ) ) ) | 
						
							| 46 | 18 2 | latjass |  |-  ( ( K e. Lat /\ ( ( P .\/ Q ) e. ( Base ` K ) /\ R e. ( Base ` K ) /\ S e. ( Base ` K ) ) ) -> ( ( ( P .\/ Q ) .\/ R ) .\/ S ) = ( ( P .\/ Q ) .\/ ( R .\/ S ) ) ) | 
						
							| 47 | 17 20 40 42 46 | syl13anc |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( ( P .\/ Q ) .\/ R ) .\/ S ) = ( ( P .\/ Q ) .\/ ( R .\/ S ) ) ) | 
						
							| 48 | 47 | breq1d |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( ( ( P .\/ Q ) .\/ R ) .\/ S ) .<_ ( ( T .\/ U ) .\/ V ) <-> ( ( P .\/ Q ) .\/ ( R .\/ S ) ) .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 49 | 30 45 48 | 3bitr4d |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) /\ ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) ) <-> ( ( ( P .\/ Q ) .\/ R ) .\/ S ) .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 50 | 16 49 | mtbird |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> -. ( ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) /\ ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) ) ) | 
						
							| 51 |  | ianor |  |-  ( -. ( ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) /\ ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) ) <-> ( -. ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) \/ -. ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) ) ) | 
						
							| 52 |  | ianor |  |-  ( -. ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) <-> ( -. P .<_ ( ( T .\/ U ) .\/ V ) \/ -. Q .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 53 |  | ianor |  |-  ( -. ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) <-> ( -. R .<_ ( ( T .\/ U ) .\/ V ) \/ -. S .<_ ( ( T .\/ U ) .\/ V ) ) ) | 
						
							| 54 | 52 53 | orbi12i |  |-  ( ( -. ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) \/ -. ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) ) <-> ( ( -. P .<_ ( ( T .\/ U ) .\/ V ) \/ -. Q .<_ ( ( T .\/ U ) .\/ V ) ) \/ ( -. R .<_ ( ( T .\/ U ) .\/ V ) \/ -. S .<_ ( ( T .\/ U ) .\/ V ) ) ) ) | 
						
							| 55 | 51 54 | bitri |  |-  ( -. ( ( P .<_ ( ( T .\/ U ) .\/ V ) /\ Q .<_ ( ( T .\/ U ) .\/ V ) ) /\ ( R .<_ ( ( T .\/ U ) .\/ V ) /\ S .<_ ( ( T .\/ U ) .\/ V ) ) ) <-> ( ( -. P .<_ ( ( T .\/ U ) .\/ V ) \/ -. Q .<_ ( ( T .\/ U ) .\/ V ) ) \/ ( -. R .<_ ( ( T .\/ U ) .\/ V ) \/ -. S .<_ ( ( T .\/ U ) .\/ V ) ) ) ) | 
						
							| 56 | 50 55 | sylib |  |-  ( ( ( ( K e. HL /\ P e. A /\ Q e. A ) /\ ( R e. A /\ S e. A /\ T e. A ) /\ ( U e. A /\ V e. A ) ) /\ ( P =/= Q /\ -. R .<_ ( P .\/ Q ) /\ -. S .<_ ( ( P .\/ Q ) .\/ R ) ) ) -> ( ( -. P .<_ ( ( T .\/ U ) .\/ V ) \/ -. Q .<_ ( ( T .\/ U ) .\/ V ) ) \/ ( -. R .<_ ( ( T .\/ U ) .\/ V ) \/ -. S .<_ ( ( T .\/ U ) .\/ V ) ) ) ) |