let L be complete continuous LATTICE; for p being kernel Function of L,L st p is directed-sups-preserving holds
Image p is continuous LATTICE
let p be kernel Function of L,L; ( p is directed-sups-preserving implies Image p is continuous LATTICE )
assume A1:
p is directed-sups-preserving
; Image p is continuous LATTICE
now for X being Subset of L st not X is empty & X is directed holds
corestr p preserves_sup_of Xlet X be
Subset of
L;
( not X is empty & X is directed implies corestr p preserves_sup_of X )assume
( not
X is
empty &
X is
directed )
;
corestr p preserves_sup_of Xthen A2:
p preserves_sup_of X
by A1, WAYBEL_0:def 37;
A3:
Image p is
sups-inheriting
by WAYBEL_1:53;
now ( ex_sup_of X,L implies ( ex_sup_of (corestr p) .: X, Image p & sup ((corestr p) .: X) = (corestr p) . (sup X) ) )assume A4:
ex_sup_of X,
L
;
( ex_sup_of (corestr p) .: X, Image p & sup ((corestr p) .: X) = (corestr p) . (sup X) )
Image p is
complete
by WAYBEL_1:54;
hence
ex_sup_of (corestr p) .: X,
Image p
by YELLOW_0:17;
sup ((corestr p) .: X) = (corestr p) . (sup X)A5:
(corestr p) .: X = p .: X
by WAYBEL_1:30;
ex_sup_of p .: X,
L
by YELLOW_0:17;
then
"\/" (
((corestr p) .: X),
L)
in the
carrier of
(Image p)
by A3, A5, YELLOW_0:def 19;
hence sup ((corestr p) .: X) =
sup (p .: X)
by A5, YELLOW_0:68
.=
p . (sup X)
by A2, A4, WAYBEL_0:def 31
.=
(corestr p) . (sup X)
by WAYBEL_1:30
;
verum end; hence
corestr p preserves_sup_of X
by WAYBEL_0:def 31;
verum end;
then
corestr p is directed-sups-preserving
by WAYBEL_0:def 37;
hence
Image p is continuous LATTICE
by WAYBEL_1:56, WAYBEL_5:33; verum