let L be complete Semilattice; :: thesis: ( ( for x being Element of L
for J being set
for f being Function of J,the carrier of L holds x "/\" (Sup ) = sup (x "/\" (FinSups f)) ) implies for x being Element of L
for N being prenet of L st N is eventually-directed holds
x "/\" (sup N) = sup ({x} "/\" (rng (netmap N,L))) )
assume A1:
for x being Element of L
for J being set
for f being Function of J,the carrier of L holds x "/\" (Sup ) = sup (x "/\" (FinSups f))
; :: thesis: for x being Element of L
for N being prenet of L st N is eventually-directed holds
x "/\" (sup N) = sup ({x} "/\" (rng (netmap N,L)))
let x be Element of L; :: thesis: for N being prenet of L st N is eventually-directed holds
x "/\" (sup N) = sup ({x} "/\" (rng (netmap N,L)))
let N be prenet of L; :: thesis: ( N is eventually-directed implies x "/\" (sup N) = sup ({x} "/\" (rng (netmap N,L))) )
assume A2:
N is eventually-directed
; :: thesis: x "/\" (sup N) = sup ({x} "/\" (rng (netmap N,L)))
set f = the mapping of N;
reconsider R = rng (netmap N,L) as non empty directed Subset of L by A2, Th18;
A3:
ex_sup_of R,L
by WAYBEL_0:75;
reconsider xx = {x} as non empty directed Subset of L by WAYBEL_0:5;
A4:
ex_sup_of xx "/\" R,L
by WAYBEL_0:75;
Sup = "\/" (rng (netmap N,L)),L
by YELLOW_2:def 5;
then A5:
sup ({x} "/\" (rng (netmap N,L))) <= x "/\" (Sup )
by A3, A4, YELLOW_4:53;
A6:
sup (x "/\" (FinSups the mapping of N)) = "\/" (rng the mapping of (x "/\" (FinSups the mapping of N))),L
by YELLOW_2:def 5;
set h = the mapping of (FinSups the mapping of N);
x "/\" (FinSups the mapping of N) is eventually-directed
by Th27;
then
rng (netmap (x "/\" (FinSups the mapping of N)),L) is directed
by Th18;
then A7:
ex_sup_of rng the mapping of (x "/\" (FinSups the mapping of N)),L
by WAYBEL_0:75;
rng the mapping of (x "/\" (FinSups the mapping of N)) is_<=_than sup ({x} "/\" (rng (netmap N,L)))
proof
let a be
Element of
L;
:: according to LATTICE3:def 9 :: thesis: ( not a in rng the mapping of (x "/\" (FinSups the mapping of N)) or a <= sup ({x} "/\" (rng (netmap N,L))) )
assume
a in rng the
mapping of
(x "/\" (FinSups the mapping of N))
;
:: thesis: a <= sup ({x} "/\" (rng (netmap N,L)))
then A8:
a in {x} "/\" (rng the mapping of (FinSups the mapping of N))
by Th23;
{x} "/\" (rng the mapping of (FinSups the mapping of N)) = { (x "/\" y) where y is Element of L : y in rng the mapping of (FinSups the mapping of N) }
by YELLOW_4:42;
then consider y being
Element of
L such that A9:
(
a = x "/\" y &
y in rng the
mapping of
(FinSups the mapping of N) )
by A8;
for
x being
set holds
ex_sup_of the
mapping of
N .: x,
L
by YELLOW_0:17;
then
rng (netmap (FinSups the mapping of N),L) c= finsups (rng the mapping of N)
by Th24;
then
y in finsups (rng the mapping of N)
by A9;
then consider Y being
finite Subset of
(rng the mapping of N) such that A10:
(
y = "\/" Y,
L &
ex_sup_of Y,
L )
;
rng (netmap N,L) is
directed
by A2, Th18;
then consider z being
Element of
L such that A11:
(
z in rng the
mapping of
N &
z is_>=_than Y )
by WAYBEL_0:1;
A12:
"\/" Y,
L <= z
by A10, A11, YELLOW_0:30;
x in {x}
by TARSKI:def 1;
then A13:
x "/\" z <= sup (xx "/\" (rng the mapping of N))
by A4, A11, YELLOW_4:1, YELLOW_4:37;
x <= x
;
then
x "/\" y <= x "/\" z
by A10, A12, YELLOW_3:2;
hence
a <= sup ({x} "/\" (rng (netmap N,L)))
by A9, A13, YELLOW_0:def 2;
:: thesis: verum
end;
then
"\/" (rng the mapping of (x "/\" (FinSups the mapping of N))),L <= sup ({x} "/\" (rng (netmap N,L)))
by A7, YELLOW_0:def 9;
then
x "/\" (Sup ) <= sup ({x} "/\" (rng (netmap N,L)))
by A1, A6;
hence
x "/\" (sup N) = sup ({x} "/\" (rng (netmap N,L)))
by A5, ORDERS_2:25; :: thesis: verum