Metamath Proof Explorer


Theorem dalempjsen

Description: Lemma for dath . Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012)

Ref Expression
Hypotheses dalema.ph
|- ( ph <-> ( ( ( K e. HL /\ C e. ( Base ` K ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) /\ ( Y e. O /\ Z e. O ) /\ ( ( -. C .<_ ( P .\/ Q ) /\ -. C .<_ ( Q .\/ R ) /\ -. C .<_ ( R .\/ P ) ) /\ ( -. C .<_ ( S .\/ T ) /\ -. C .<_ ( T .\/ U ) /\ -. C .<_ ( U .\/ S ) ) /\ ( C .<_ ( P .\/ S ) /\ C .<_ ( Q .\/ T ) /\ C .<_ ( R .\/ U ) ) ) ) )
dalemc.l
|- .<_ = ( le ` K )
dalemc.j
|- .\/ = ( join ` K )
dalemc.a
|- A = ( Atoms ` K )
dalempnes.o
|- O = ( LPlanes ` K )
dalempnes.y
|- Y = ( ( P .\/ Q ) .\/ R )
Assertion dalempjsen
|- ( ph -> ( P .\/ S ) e. ( LLines ` K ) )

Proof

Step Hyp Ref Expression
1 dalema.ph
 |-  ( ph <-> ( ( ( K e. HL /\ C e. ( Base ` K ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) /\ ( Y e. O /\ Z e. O ) /\ ( ( -. C .<_ ( P .\/ Q ) /\ -. C .<_ ( Q .\/ R ) /\ -. C .<_ ( R .\/ P ) ) /\ ( -. C .<_ ( S .\/ T ) /\ -. C .<_ ( T .\/ U ) /\ -. C .<_ ( U .\/ S ) ) /\ ( C .<_ ( P .\/ S ) /\ C .<_ ( Q .\/ T ) /\ C .<_ ( R .\/ U ) ) ) ) )
2 dalemc.l
 |-  .<_ = ( le ` K )
3 dalemc.j
 |-  .\/ = ( join ` K )
4 dalemc.a
 |-  A = ( Atoms ` K )
5 dalempnes.o
 |-  O = ( LPlanes ` K )
6 dalempnes.y
 |-  Y = ( ( P .\/ Q ) .\/ R )
7 1 dalemkehl
 |-  ( ph -> K e. HL )
8 1 dalempea
 |-  ( ph -> P e. A )
9 1 dalemsea
 |-  ( ph -> S e. A )
10 1 2 3 4 5 6 dalempnes
 |-  ( ph -> P =/= S )
11 eqid
 |-  ( LLines ` K ) = ( LLines ` K )
12 3 4 11 llni2
 |-  ( ( ( K e. HL /\ P e. A /\ S e. A ) /\ P =/= S ) -> ( P .\/ S ) e. ( LLines ` K ) )
13 7 8 9 10 12 syl31anc
 |-  ( ph -> ( P .\/ S ) e. ( LLines ` K ) )