Metamath Proof Explorer


Theorem latmlej11

Description: Ordering of a meet and join with a common variable. (Contributed by NM, 4-Oct-2012)

Ref Expression
Hypotheses latledi.b
|- B = ( Base ` K )
latledi.l
|- .<_ = ( le ` K )
latledi.j
|- .\/ = ( join ` K )
latledi.m
|- ./\ = ( meet ` K )
Assertion latmlej11
|- ( ( K e. Lat /\ ( X e. B /\ Y e. B /\ Z e. B ) ) -> ( X ./\ Y ) .<_ ( X .\/ Z ) )

Proof

Step Hyp Ref Expression
1 latledi.b
 |-  B = ( Base ` K )
2 latledi.l
 |-  .<_ = ( le ` K )
3 latledi.j
 |-  .\/ = ( join ` K )
4 latledi.m
 |-  ./\ = ( meet ` K )
5 simpl
 |-  ( ( K e. Lat /\ ( X e. B /\ Y e. B /\ Z e. B ) ) -> K e. Lat )
6 1 4 latmcl
 |-  ( ( K e. Lat /\ X e. B /\ Y e. B ) -> ( X ./\ Y ) e. B )
7 6 3adant3r3
 |-  ( ( K e. Lat /\ ( X e. B /\ Y e. B /\ Z e. B ) ) -> ( X ./\ Y ) e. B )
8 simpr1
 |-  ( ( K e. Lat /\ ( X e. B /\ Y e. B /\ Z e. B ) ) -> X e. B )
9 1 3 latjcl
 |-  ( ( K e. Lat /\ X e. B /\ Z e. B ) -> ( X .\/ Z ) e. B )
10 9 3adant3r2
 |-  ( ( K e. Lat /\ ( X e. B /\ Y e. B /\ Z e. B ) ) -> ( X .\/ Z ) e. B )
11 1 2 4 latmle1
 |-  ( ( K e. Lat /\ X e. B /\ Y e. B ) -> ( X ./\ Y ) .<_ X )
12 11 3adant3r3
 |-  ( ( K e. Lat /\ ( X e. B /\ Y e. B /\ Z e. B ) ) -> ( X ./\ Y ) .<_ X )
13 1 2 3 latlej1
 |-  ( ( K e. Lat /\ X e. B /\ Z e. B ) -> X .<_ ( X .\/ Z ) )
14 13 3adant3r2
 |-  ( ( K e. Lat /\ ( X e. B /\ Y e. B /\ Z e. B ) ) -> X .<_ ( X .\/ Z ) )
15 1 2 5 7 8 10 12 14 lattrd
 |-  ( ( K e. Lat /\ ( X e. B /\ Y e. B /\ Z e. B ) ) -> ( X ./\ Y ) .<_ ( X .\/ Z ) )