let S, T be complete LATTICE; for g being infs-preserving Function of S,T
for X being Scott TopAugmentation of T
for Y being Scott TopAugmentation of S st ( for V being open Subset of X holds uparrow ((LowerAdj g) .: V) is open Subset of Y ) holds
for d being Function of X,Y st d = LowerAdj g holds
d is relatively_open
let g be infs-preserving Function of S,T; for X being Scott TopAugmentation of T
for Y being Scott TopAugmentation of S st ( for V being open Subset of X holds uparrow ((LowerAdj g) .: V) is open Subset of Y ) holds
for d being Function of X,Y st d = LowerAdj g holds
d is relatively_open
let X be Scott TopAugmentation of T; for Y being Scott TopAugmentation of S st ( for V being open Subset of X holds uparrow ((LowerAdj g) .: V) is open Subset of Y ) holds
for d being Function of X,Y st d = LowerAdj g holds
d is relatively_open
let Y be Scott TopAugmentation of S; ( ( for V being open Subset of X holds uparrow ((LowerAdj g) .: V) is open Subset of Y ) implies for d being Function of X,Y st d = LowerAdj g holds
d is relatively_open )
assume A1:
for V being open Subset of X holds uparrow ((LowerAdj g) .: V) is open Subset of Y
; for d being Function of X,Y st d = LowerAdj g holds
d is relatively_open
let d be Function of X,Y; ( d = LowerAdj g implies d is relatively_open )
assume A2:
d = LowerAdj g
; d is relatively_open
let V be open Subset of X; WAYBEL34:def 9 d .: V is open Subset of (Y | (rng d))
reconsider A = uparrow ((LowerAdj g) .: V) as open Subset of Y by A1;
d .: V = A /\ (rng d)
by A2, Th25;
then A3:
d .: V = ([#] (Y | (rng d))) /\ A
by PRE_TOPC:def 5;
A4:
A in the topology of Y
by PRE_TOPC:def 2;
reconsider B = d .: V as Subset of (Y | (rng d)) by A3, XBOOLE_1:17;
B in the topology of (Y | (rng d))
by A3, A4, PRE_TOPC:def 4;
hence
d .: V is open Subset of (Y | (rng d))
by PRE_TOPC:def 2; verum