let L be complete noetherian Lattice; :: thesis: JIRRS L is supremum-dense
defpred S1[ Element of (LattPOSet L)] means ex D' being Subset of (JIRRS L) st % $1 = "\/" D',L;
A1:
LattPOSet L is well_founded
by Def3;
A2:
for x being Element of (LattPOSet L) st ( for y being Element of (LattPOSet L) st y <> x & [y,x] in the InternalRel of (LattPOSet L) holds
S1[y] ) holds
S1[x]
proof
let x be
Element of
(LattPOSet L);
:: thesis: ( ( for y being Element of (LattPOSet L) st y <> x & [y,x] in the InternalRel of (LattPOSet L) holds
S1[y] ) implies S1[x] )
assume A3:
for
y being
Element of
(LattPOSet L) st
y <> x &
[y,x] in the
InternalRel of
(LattPOSet L) holds
S1[
y]
;
:: thesis: S1[x]
set X =
{ d where d is Element of L : ( d [= % x & d <> % x ) } ;
A4:
for
u being
Element of
L st
u in { d where d is Element of L : ( d [= % x & d <> % x ) } holds
(
u % <> x &
[(u % ),x] in the
InternalRel of
(LattPOSet L) )
A7:
for
u being
Element of
L st
u in { d where d is Element of L : ( d [= % x & d <> % x ) } holds
S1[
u % ]
per cases
( % x is completely-join-irreducible or not % x is completely-join-irreducible )
;
suppose
not
% x is
completely-join-irreducible
;
:: thesis: S1[x]then A9:
*' (% x) = % x
by Def9;
set G =
{ H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } ;
set D' =
union { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } ;
for
v being
set st
v in union { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } holds
v in JIRRS L
then A12:
union { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } is
Subset of
(JIRRS L)
by TARSKI:def 3;
for
q being
Element of
L st
q in union { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } holds
q [= % x
proof
let q be
Element of
L;
:: thesis: ( q in union { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } implies q [= % x )
assume
q in union { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) }
;
:: thesis: q [= % x
then consider h being
set such that A13:
(
q in h &
h in { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } )
by TARSKI:def 4;
consider h' being
Subset of
(JIRRS L) such that A14:
(
h' = h & ex
u being
Element of
(LattPOSet L) st
(
% u in { d where d is Element of L : ( d [= % x & d <> % x ) } &
% u = "\/" h',
L ) )
by A13;
consider u being
Element of
(LattPOSet L) such that A15:
(
% u in { d where d is Element of L : ( d [= % x & d <> % x ) } &
% u = "\/" h,
L )
by A14;
h is_less_than % u
by A15, LATTICE3:def 21;
then A16:
q [= % u
by A13, LATTICE3:def 17;
{ d where d is Element of L : ( d [= % x & d <> % x ) } is_less_than % x
by A9, LATTICE3:def 21;
then
% u [= % x
by A15, LATTICE3:def 17;
hence
q [= % x
by A16, LATTICES:25;
:: thesis: verum
end; then A17:
union { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } is_less_than % x
by LATTICE3:def 17;
for
r being
Element of
L st
union { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } is_less_than r holds
% x [= r
then
% x = "\/" (union { H where H is Subset of (JIRRS L) : ex u being Element of (LattPOSet L) st
( % u in { d where d is Element of L : ( d [= % x & d <> % x ) } & % u = "\/" H,L ) } ),
L
by A17, LATTICE3:def 21;
hence
S1[
x]
by A12;
:: thesis: verum end; end;
end;
A24:
for x being Element of (LattPOSet L) holds S1[x]
from WELLFND1:sch 3(A2, A1);
for a being Element of L ex D' being Subset of (JIRRS L) st a = "\/" D',L
hence
JIRRS L is supremum-dense
by Def13; :: thesis: verum