let L be complete LATTICE; ( L is continuous implies for S being CLSubFrame of L holds S is continuous LATTICE )
assume A1:
L is continuous
; for S being CLSubFrame of L holds S is continuous LATTICE
let S be CLSubFrame of L; S is continuous LATTICE
reconsider L9 = L as complete LATTICE ;
A2:
S is complete LATTICE
by YELLOW_2:30;
for J being non empty set
for K being non-empty ManySortedSet of J
for F being DoubleIndexedSet of K,S st ( for j being Element of J holds rng (F . j) is directed ) holds
Inf = Sup
proof
let J be non
empty set ;
for K being non-empty ManySortedSet of J
for F being DoubleIndexedSet of K,S st ( for j being Element of J holds rng (F . j) is directed ) holds
Inf = Sup let K be
non-empty ManySortedSet of
J;
for F being DoubleIndexedSet of K,S st ( for j being Element of J holds rng (F . j) is directed ) holds
Inf = Sup let F be
DoubleIndexedSet of
K,
S;
( ( for j being Element of J holds rng (F . j) is directed ) implies Inf = Sup )
assume A3:
for
j being
Element of
J holds
rng (F . j) is
directed
;
Inf = Sup
then reconsider F9 =
F as
DoubleIndexedSet of
K,
L by PBOOLE:def 15;
ex_inf_of rng (Sups ),
L
by YELLOW_0:17;
then A6:
"/\" (
(rng (Sups )),
L)
in the
carrier of
S
by YELLOW_0:def 18;
then A9:
rng (Sups ) c= rng (Sups )
;
then
rng (Sups ) c= rng (Sups )
;
then
(
ex_inf_of rng (Sups ),
L9 &
rng (Sups ) = rng (Sups ) )
by A9, XBOOLE_0:def 10, YELLOW_0:17;
then
inf (rng (Sups )) = inf (rng (Sups ))
by A6, YELLOW_0:63;
then A12:
Inf = inf (rng (Sups ))
by YELLOW_2:def 6;
now for x being object st x in rng (Infs ) holds
x in rng (Infs )let x be
object ;
( x in rng (Infs ) implies x in rng (Infs ) )assume
x in rng (Infs )
;
x in rng (Infs )then consider f being
object such that A13:
f in dom (Frege F)
and A14:
x = //\ (
((Frege F) . f),
S)
by Th13;
reconsider f =
f as
Function by A13;
(Frege F) . f is
Function of
J, the
carrier of
S
by A13, Th10;
then A15:
rng ((Frege F) . f) c= the
carrier of
S
by RELAT_1:def 19;
A16:
ex_inf_of rng ((Frege F) . f),
L9
by YELLOW_0:17;
then A17:
"/\" (
(rng ((Frege F) . f)),
L)
in the
carrier of
S
by A15, YELLOW_0:def 18;
x =
"/\" (
(rng ((Frege F) . f)),
S)
by A14, YELLOW_2:def 6
.=
"/\" (
(rng ((Frege F9) . f)),
L)
by A15, A16, A17, YELLOW_0:63
.=
//\ (
((Frege F9) . f),
L)
by YELLOW_2:def 6
;
hence
x in rng (Infs )
by A13, Th13;
verum end;
then A18:
rng (Infs ) c= rng (Infs )
;
now for x being object st x in rng (/\\ ((Frege F9),L)) holds
x in rng (Infs )let x be
object ;
( x in rng (/\\ ((Frege F9),L)) implies x in rng (Infs ) )assume
x in rng (/\\ ((Frege F9),L))
;
x in rng (Infs )then consider f being
object such that A19:
f in dom (Frege F9)
and A20:
x = //\ (
((Frege F9) . f),
L)
by Th13;
reconsider f =
f as
Element of
product (doms F9) by A19;
(Frege F) . f is
Function of
J, the
carrier of
S
by A19, Th10;
then A21:
rng ((Frege F) . f) c= the
carrier of
S
by RELAT_1:def 19;
A22:
ex_inf_of rng ((Frege F) . f),
L9
by YELLOW_0:17;
then A23:
"/\" (
(rng ((Frege F) . f)),
L)
in the
carrier of
S
by A21, YELLOW_0:def 18;
x =
"/\" (
(rng ((Frege F9) . f)),
L)
by A20, YELLOW_2:def 6
.=
"/\" (
(rng ((Frege F) . f)),
S)
by A21, A22, A23, YELLOW_0:63
.=
//\ (
((Frege F) . f),
S)
by YELLOW_2:def 6
;
hence
x in rng (Infs )
by A19, Th13;
verum end;
then
rng (/\\ ((Frege F9),L)) c= rng (/\\ ((Frege F),S))
;
then A24:
rng (Infs ) = rng (Infs )
by A18, XBOOLE_0:def 10;
for
j being
Element of
J holds
rng (F9 . j) is
directed
then A25:
Inf = Sup
by A1, Lm8;
(
ex_sup_of rng (/\\ ((Frege F9),L)),
L9 &
rng (Infs ) is non
empty directed Subset of
S )
by A2, A3, Th27, YELLOW_0:17;
then
sup (rng (Infs )) = sup (rng (Infs ))
by A24, WAYBEL_0:7;
then Sup =
sup (rng (Infs ))
by YELLOW_2:def 5
.=
Sup
by YELLOW_2:def 5
;
hence
Inf = Sup
by A25, A12, YELLOW_2:def 6;
verum
end;
hence
S is continuous LATTICE
by A2, Lm9; verum