let L be complete LATTICE; for c being closure Function of L,L holds
( Image c is directed-sups-inheriting iff for X being Scott TopAugmentation of Image c
for Y being Scott TopAugmentation of L
for f being Function of Y,X st f = c holds
f is open )
let c be closure Function of L,L; ( Image c is directed-sups-inheriting iff for X being Scott TopAugmentation of Image c
for Y being Scott TopAugmentation of L
for f being Function of Y,X st f = c holds
f is open )
A1:
LowerAdj (inclusion c) = corestr c
by Th35;
A2:
corestr c = c
by WAYBEL_1:30;
A3:
inclusion c is infs-preserving Function of (Image c),L
by Th35;
A4:
( Image c is directed-sups-inheriting iff inclusion c is directed-sups-preserving )
by Th36;
hence
( Image c is directed-sups-inheriting implies for X being Scott TopAugmentation of Image c
for Y being Scott TopAugmentation of L
for f being Function of Y,X st f = c holds
f is open )
by A1, A2, A3, Th28; ( ( for X being Scott TopAugmentation of Image c
for Y being Scott TopAugmentation of L
for f being Function of Y,X st f = c holds
f is open ) implies Image c is directed-sups-inheriting )
assume A5:
for X being Scott TopAugmentation of Image c
for Y being Scott TopAugmentation of L
for f being Function of Y,X st f = c holds
f is open
; Image c is directed-sups-inheriting
set X = the Scott TopAugmentation of Image c;
set Y = the Scott TopAugmentation of L;
A6:
RelStr(# the carrier of the Scott TopAugmentation of Image c, the InternalRel of the Scott TopAugmentation of Image c #) = RelStr(# the carrier of (Image c), the InternalRel of (Image c) #)
by YELLOW_9:def 4;
RelStr(# the carrier of the Scott TopAugmentation of L, the InternalRel of the Scott TopAugmentation of L #) = RelStr(# the carrier of L, the InternalRel of L #)
by YELLOW_9:def 4;
then reconsider f = c as Function of the Scott TopAugmentation of L, the Scott TopAugmentation of Image c by A2, A6;
f is open
by A5;
hence
Image c is directed-sups-inheriting
by A1, A2, A3, A4, Th28; verum