let T be non empty TopSpace; ( ( T is regular & T is T_1 & ex Bn being FamilySequence of T st Bn is Basis_sigma_locally_finite ) iff T is metrizable )
thus
( T is regular & T is T_1 & ex Bn being FamilySequence of T st Bn is Basis_sigma_locally_finite implies T is metrizable )
( T is metrizable implies ( T is regular & T is T_1 & ex Bn being FamilySequence of T st Bn is Basis_sigma_locally_finite ) )proof
set cTT = the
carrier of
[:T,T:];
set bcT =
bool the
carrier of
T;
set cT = the
carrier of
T;
assume that A1:
T is
regular
and A2:
T is
T_1
and A3:
ex
Bn being
FamilySequence of
T st
Bn is
Basis_sigma_locally_finite
;
T is metrizable
set Fun =
Funcs ( the
carrier of
[:T,T:],
REAL);
consider Bn being
FamilySequence of
T such that A4:
Bn is
Basis_sigma_locally_finite
by A3;
defpred S1[
object ,
object ,
RealMap of
[:T,T:]]
means ex
pmet being
Function of
[: the carrier of T, the carrier of T:],
REAL st
( $3
= pmet & $3 is
continuous &
pmet is_a_pseudometric_of the
carrier of
T & ( for
p,
q being
Point of
T holds
(
pmet . [p,q] <= 1 & ( for
p,
q being
Point of
T st ex
A,
B being
Subset of
T st
(
A is
open &
B is
open &
A in Bn . $2 &
B in Bn . $1 &
p in A &
Cl A c= B & not
q in B ) holds
pmet . [p,q] = 1 ) ) ) );
defpred S2[
object ,
object ]
means ex
F being
RealMap of
[:T,T:] st
(
F = $2 & ( for
n,
m being
Nat st
(PairFunc ") . $1
= [n,m] holds
S1[
n,
m,
F] ) );
A5:
Union Bn is
Basis of
T
by A4, NAGATA_1:def 6;
A6:
Bn is
sigma_locally_finite
by A4, NAGATA_1:def 6;
A7:
for
n,
m being
Nat ex
pmet9 being
RealMap of
[:T,T:] st
S1[
n,
m,
pmet9]
proof
defpred S3[
Element of
Funcs ( the
carrier of
[:T,T:],
REAL),
Element of
Funcs ( the
carrier of
[:T,T:],
REAL),
set ]
means $1
+ $2
= $3;
defpred S4[
RealMap of
T,
Function]
means for
p,
q being
Point of
T holds $2
. (
p,
q)
= |.(($1 . p) - ($1 . q)).|;
let n,
m be
Nat;
ex pmet9 being RealMap of [:T,T:] st S1[n,m,pmet9]
deffunc H1(
object )
-> set =
union { Q where Q is Subset of T : ex D1 being set st
( D1 = $1 & Q in Bn . m & Cl Q c= D1 ) } ;
set Bnn =
Bn . n;
deffunc H2(
Subset of
T)
-> set =
{ Q where Q is Subset of T : ( Q in Bn . n & Q meets $1 ) } ;
defpred S5[
set ,
Subset of
T]
means ( $1
in $2 & $2 is
open &
H2($2) is
finite );
A8:
for
A being
object st
A in bool the
carrier of
T holds
H1(
A)
in bool the
carrier of
T
consider Vm being
Function of
(bool the carrier of T),
(bool the carrier of T) such that A11:
for
A being
object st
A in bool the
carrier of
T holds
Vm . A = H1(
A)
from FUNCT_2:sch 2(A8);
defpred S6[
object ,
object ]
means ex
F being
RealMap of
T ex
S being
Subset of
T st
(
S = $1 &
F = $2 &
F is
continuous & ( for
p being
Point of
T holds
(
0 <= F . p &
F . p <= 1 & (
p in S ` implies
F . p = 0 ) & (
p in Cl (Vm . S) implies
F . p = 1 ) ) ) );
A12:
m in NAT
by ORDINAL1:def 12;
A13:
Bn . m is
locally_finite
by A6, NAGATA_1:def 3, A12;
A14:
for
A being
Subset of
T holds
Cl (Vm . A) c= A
A21:
for
A being
object st
A in Bn . n holds
ex
f being
object st
(
f in Funcs ( the
carrier of
T,
REAL) &
S6[
A,
f] )
proof
let A be
object ;
( A in Bn . n implies ex f being object st
( f in Funcs ( the carrier of T,REAL) & S6[A,f] ) )
assume
A in Bn . n
;
ex f being object st
( f in Funcs ( the carrier of T,REAL) & S6[A,f] )
then A22:
A in Union Bn
by PROB_1:12;
Union Bn c= the
topology of
T
by A5, TOPS_2:64;
then reconsider A =
A as
open Subset of
T by A22, PRE_TOPC:def 2;
A ` misses A
by XBOOLE_1:79;
then A23:
A ` misses Cl (Vm . A)
by A14, XBOOLE_1:63;
T is
normal
by A1, A4, NAGATA_1:20;
then consider f being
Function of
T,
R^1 such that A24:
(
f is
continuous & ( for
p being
Point of
T holds
(
0 <= f . p &
f . p <= 1 & (
p in A ` implies
f . p = 0 ) & (
p in Cl (Vm . A) implies
f . p = 1 ) ) ) )
by A23, URYSOHN3:20;
reconsider f9 =
f as
RealMap of
T by TOPMETR:17;
A25:
ex
F being
RealMap of
T ex
S being
Subset of
T st
(
S = A &
F = f9 &
F is
continuous & ( for
p being
Point of
T holds
(
0 <= F . p &
F . p <= 1 & (
p in S ` implies
F . p = 0 ) & (
p in Cl (Vm . S) implies
F . p = 1 ) ) ) )
f9 in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
hence
ex
f being
object st
(
f in Funcs ( the
carrier of
T,
REAL) &
S6[
A,
f] )
by A25;
verum
end;
consider Fn being
Function of
(Bn . n),
(Funcs ( the carrier of T,REAL)) such that A26:
for
A being
object st
A in Bn . n holds
S6[
A,
Fn . A]
from FUNCT_2:sch 1(A21);
A27:
n in NAT
by ORDINAL1:def 12;
Bn . n is
locally_finite
by A6, NAGATA_1:def 3, A27;
then A28:
for
p being
Element of the
carrier of
T ex
A being
Element of
bool the
carrier of
T st
S5[
p,
A]
by PCOMPS_1:def 1;
consider Sx being
Function of the
carrier of
T,
(bool the carrier of T) such that A29:
for
p being
Element of the
carrier of
T holds
S5[
p,
Sx . p]
from FUNCT_2:sch 3(A28);
defpred S7[
object ,
object ]
means for
x,
y being
Element of
T st $1
= [x,y] holds
$2
= [:(Sx . x),(Sx . y):];
A30:
for
pq9 being
object st
pq9 in the
carrier of
[:T,T:] holds
ex
SS being
object st
(
SS in bool the
carrier of
[:T,T:] &
S7[
pq9,
SS] )
proof
let pq9 be
object ;
( pq9 in the carrier of [:T,T:] implies ex SS being object st
( SS in bool the carrier of [:T,T:] & S7[pq9,SS] ) )
assume
pq9 in the
carrier of
[:T,T:]
;
ex SS being object st
( SS in bool the carrier of [:T,T:] & S7[pq9,SS] )
then
pq9 in [: the carrier of T, the carrier of T:]
by BORSUK_1:def 2;
then consider p,
q being
object such that A31:
(
p in the
carrier of
T &
q in the
carrier of
T )
and A32:
pq9 = [p,q]
by ZFMISC_1:def 2;
reconsider p =
p,
q =
q as
Point of
T by A31;
now for p1, q1 being Point of T st pq9 = [p1,q1] holds
[:(Sx . p),(Sx . q):] = [:(Sx . p1),(Sx . q1):]let p1,
q1 be
Point of
T;
( pq9 = [p1,q1] implies [:(Sx . p),(Sx . q):] = [:(Sx . p1),(Sx . q1):] )assume A33:
pq9 = [p1,q1]
;
[:(Sx . p),(Sx . q):] = [:(Sx . p1),(Sx . q1):]then
p1 = p
by A32, XTUPLE_0:1;
hence
[:(Sx . p),(Sx . q):] = [:(Sx . p1),(Sx . q1):]
by A32, A33, XTUPLE_0:1;
verum end;
hence
ex
SS being
object st
(
SS in bool the
carrier of
[:T,T:] &
S7[
pq9,
SS] )
;
verum
end;
consider SS being
Function of the
carrier of
[:T,T:],
(bool the carrier of [:T,T:]) such that A34:
for
pq being
object st
pq in the
carrier of
[:T,T:] holds
S7[
pq,
SS . pq]
from FUNCT_2:sch 1(A30);
A35:
for
pq9 being
Point of
[:T,T:] holds
(
pq9 in SS . pq9 &
SS . pq9 is
open )
proof
let pq9 be
Point of
[:T,T:];
( pq9 in SS . pq9 & SS . pq9 is open )
pq9 in the
carrier of
[:T,T:]
;
then
pq9 in [: the carrier of T, the carrier of T:]
by BORSUK_1:def 2;
then consider p,
q being
object such that A36:
(
p in the
carrier of
T &
q in the
carrier of
T )
and A37:
pq9 = [p,q]
by ZFMISC_1:def 2;
reconsider p =
p,
q =
q as
Point of
T by A36;
A38:
(
p in Sx . p &
q in Sx . q )
by A29;
A39:
(
Sx . p is
open &
Sx . q is
open )
by A29;
SS . pq9 = [:(Sx . p),(Sx . q):]
by A34, A37;
hence
(
pq9 in SS . pq9 &
SS . pq9 is
open )
by A37, A38, A39, BORSUK_1:6, ZFMISC_1:def 2;
verum
end;
A40:
for
f,
g being
Element of
Funcs ( the
carrier of
[:T,T:],
REAL) ex
fg being
Element of
Funcs ( the
carrier of
[:T,T:],
REAL) st
S3[
f,
g,
fg]
proof
let f,
g be
Element of
Funcs ( the
carrier of
[:T,T:],
REAL);
ex fg being Element of Funcs ( the carrier of [:T,T:],REAL) st S3[f,g,fg]
set f9 =
f;
set g9 =
g;
f + g in Funcs ( the
carrier of
[:T,T:],
REAL)
by FUNCT_2:8;
hence
ex
fg being
Element of
Funcs ( the
carrier of
[:T,T:],
REAL) st
S3[
f,
g,
fg]
;
verum
end;
consider ADD being
BinOp of
(Funcs ( the carrier of [:T,T:],REAL)) such that A41:
for
f,
g being
Element of
Funcs ( the
carrier of
[:T,T:],
REAL) holds
S3[
f,
g,
ADD . (
f,
g)]
from BINOP_1:sch 3(A40);
A42:
for
f being
Element of
Funcs ( the
carrier of
T,
REAL) ex
fxy being
Element of
Funcs ( the
carrier of
[:T,T:],
REAL) st
S4[
f,
fxy]
proof
let f be
Element of
Funcs ( the
carrier of
T,
REAL);
ex fxy being Element of Funcs ( the carrier of [:T,T:],REAL) st S4[f,fxy]
defpred S8[
Element of
T,
Element of
T,
object ]
means $3
= |.((f . $1) - (f . $2)).|;
A43:
for
x,
y being
Element of the
carrier of
T ex
r being
Element of
REAL st
S8[
x,
y,
r]
consider Fd being
Function of
[: the carrier of T, the carrier of T:],
REAL such that A45:
for
x,
y being
Element of the
carrier of
T holds
S8[
x,
y,
Fd . (
x,
y)]
from BINOP_1:sch 3(A43);
[: the carrier of T, the carrier of T:] = the
carrier of
[:T,T:]
by BORSUK_1:def 2;
then
Fd in Funcs ( the
carrier of
[:T,T:],
REAL)
by FUNCT_2:8;
hence
ex
fxy being
Element of
Funcs ( the
carrier of
[:T,T:],
REAL) st
S4[
f,
fxy]
by A45;
verum
end;
consider Fdist being
Function of
(Funcs ( the carrier of T,REAL)),
(Funcs ( the carrier of [:T,T:],REAL)) such that A46:
for
fd being
Element of
Funcs ( the
carrier of
T,
REAL) holds
S4[
fd,
Fdist . fd]
from FUNCT_2:sch 3(A42);
deffunc H3(
Element of
T)
-> set =
{ (Fn . A) where A is Subset of T : ( A in Bn . n & A in H2(Sx . $1) ) } ;
deffunc H4(
set )
-> set =
{ (Fdist . fd) where fd is RealMap of T : fd in $1 } ;
defpred S8[
set ,
Function]
means ( $2 is
one-to-one & ex
p,
q being
Point of
T st
(
[p,q] = $1 &
rng $2
= H4(
H3(
p)
\/ H3(
q)) ) );
A47:
for
p being
Point of
T holds
H3(
p) is
finite
A50:
for
p,
q being
Point of
T holds
(
H4(
H3(
p)
\/ H3(
q)) is
finite &
H4(
H3(
p)
\/ H3(
q))
c= Funcs ( the
carrier of
[:T,T:],
REAL) )
proof
deffunc H5(
RealMap of
T)
-> set =
Fdist . $1;
let p,
q be
Point of
T;
( H4(H3(p) \/ H3(q)) is finite & H4(H3(p) \/ H3(q)) c= Funcs ( the carrier of [:T,T:],REAL) )
A51:
H4(
H3(
p)
\/ H3(
q))
c= Funcs ( the
carrier of
[:T,T:],
REAL)
set RNG9 =
{ H5(fd) where fd is Element of Funcs ( the carrier of T,REAL) : fd in H3(p) \/ H3(q) } ;
A53:
H4(
H3(
p)
\/ H3(
q))
c= { H5(fd) where fd is Element of Funcs ( the carrier of T,REAL) : fd in H3(p) \/ H3(q) }
(
H3(
p) is
finite &
H3(
q) is
finite )
by A47;
then A55:
H3(
p)
\/ H3(
q) is
finite
;
{ H5(fd) where fd is Element of Funcs ( the carrier of T,REAL) : fd in H3(p) \/ H3(q) } is
finite
from FRAENKEL:sch 21(A55);
hence
(
H4(
H3(
p)
\/ H3(
q)) is
finite &
H4(
H3(
p)
\/ H3(
q))
c= Funcs ( the
carrier of
[:T,T:],
REAL) )
by A51, A53;
verum
end;
A56:
for
pq being
Element of the
carrier of
[:T,T:] ex
G being
Element of
(Funcs ( the carrier of [:T,T:],REAL)) * st
S8[
pq,
G]
proof
let pq be
Element of the
carrier of
[:T,T:];
ex G being Element of (Funcs ( the carrier of [:T,T:],REAL)) * st S8[pq,G]
pq in the
carrier of
[:T,T:]
;
then
pq in [: the carrier of T, the carrier of T:]
by BORSUK_1:def 2;
then consider p,
q being
object such that A57:
(
p in the
carrier of
T &
q in the
carrier of
T )
and A58:
pq = [p,q]
by ZFMISC_1:def 2;
reconsider p =
p,
q =
q as
Point of
T by A57;
consider SF being
FinSequence such that A59:
rng SF = H4(
H3(
p)
\/ H3(
q))
and A60:
SF is
one-to-one
by A50, FINSEQ_4:58;
rng SF c= Funcs ( the
carrier of
[:T,T:],
REAL)
by A50, A59;
then reconsider SF =
SF as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by FINSEQ_1:def 4;
SF in (Funcs ( the carrier of [:T,T:],REAL)) *
by FINSEQ_1:def 11;
hence
ex
G being
Element of
(Funcs ( the carrier of [:T,T:],REAL)) * st
S8[
pq,
G]
by A58, A59, A60;
verum
end;
consider SFdist being
Function of the
carrier of
[:T,T:],
((Funcs ( the carrier of [:T,T:],REAL)) *) such that A61:
for
pq being
Element of the
carrier of
[:T,T:] holds
S8[
pq,
SFdist . pq]
from FUNCT_2:sch 3(A56);
defpred S9[
object ,
object ]
means for
FS being
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL) st
FS = SFdist . $1 holds
$2
= ADD "**" FS;
A62:
for
pq being
object st
pq in the
carrier of
[:T,T:] holds
ex
S being
object st
(
S in Funcs ( the
carrier of
[:T,T:],
REAL) &
S9[
pq,
S] )
proof
let pq be
object ;
( pq in the carrier of [:T,T:] implies ex S being object st
( S in Funcs ( the carrier of [:T,T:],REAL) & S9[pq,S] ) )
assume
pq in the
carrier of
[:T,T:]
;
ex S being object st
( S in Funcs ( the carrier of [:T,T:],REAL) & S9[pq,S] )
then
SFdist . pq in (Funcs ( the carrier of [:T,T:],REAL)) *
by FUNCT_2:5;
then reconsider SF =
SFdist . pq as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by FINSEQ_1:def 11;
for
FS being
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL) st
FS = SFdist . pq holds
ADD "**" FS = ADD "**" SF
;
hence
ex
S being
object st
(
S in Funcs ( the
carrier of
[:T,T:],
REAL) &
S9[
pq,
S] )
;
verum
end;
consider SumFdist being
Function of the
carrier of
[:T,T:],
(Funcs ( the carrier of [:T,T:],REAL)) such that A63:
for
xy being
object st
xy in the
carrier of
[:T,T:] holds
S9[
xy,
SumFdist . xy]
from FUNCT_2:sch 1(A62);
reconsider SumFdist9 =
SumFdist as
Function of the
carrier of
[:T,T:],
(Funcs ( the carrier of [:T,T:], the carrier of R^1)) by TOPMETR:17;
reconsider SumFTS9 =
SumFdist9 Toler as
RealMap of
[:T,T:] by TOPMETR:17;
the
carrier of
[:T,T:] = [: the carrier of T, the carrier of T:]
by BORSUK_1:def 2;
then reconsider SumFTS =
SumFdist9 Toler as
Function of
[: the carrier of T, the carrier of T:],
REAL by TOPMETR:17;
A64:
for
f1,
f2 being
RealMap of
[:T,T:] holds
ADD . (
f1,
f2)
= f1 + f2
A65:
for
p,
q being
Point of
T st ex
A,
B being
Subset of
T st
(
A is
open &
B is
open &
A in Bn . m &
B in Bn . n &
p in A &
Cl A c= B & not
q in B ) holds
SumFTS9 . [p,q] >= 1
proof
let p,
q be
Point of
T;
( ex A, B being Subset of T st
( A is open & B is open & A in Bn . m & B in Bn . n & p in A & Cl A c= B & not q in B ) implies SumFTS9 . [p,q] >= 1 )
assume
ex
A,
B being
Subset of
T st
(
A is
open &
B is
open &
A in Bn . m &
B in Bn . n &
p in A &
Cl A c= B & not
q in B )
;
SumFTS9 . [p,q] >= 1
then consider A,
B being
Subset of
T such that
A is
open
and
B is
open
and A66:
A in Bn . m
and A67:
B in Bn . n
and A68:
p in A
and A69:
Cl A c= B
and A70:
not
q in B
;
A71:
S6[
B,
Fn . B]
by A26, A67;
A in { Q where Q is Subset of T : ex D1 being set st
( D1 = B & Q in Bn . m & Cl Q c= D1 ) }
by A66, A69;
then
A c= H1(
B)
by ZFMISC_1:74;
then A72:
A c= Vm . B
by A11;
Vm . B c= Cl (Vm . B)
by PRE_TOPC:18;
then A73:
p in Cl (Vm . B)
by A68, A72;
(
Cl (Vm . B) c= B &
p in Sx . p )
by A14, A29;
then
Sx . p meets B
by A73, XBOOLE_0:3;
then A74:
B in H2(
Sx . p)
by A67;
reconsider pq =
[p,q] as
Point of
[:T,T:] by BORSUK_1:def 2;
reconsider SF =
SFdist . pq as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by FINSEQ_1:def 11;
consider x,
y being
Point of
T such that A75:
[x,y] = pq
and A76:
rng SF = H4(
H3(
x)
\/ H3(
y))
by A61;
reconsider ASF =
ADD "**" SF as
RealMap of
[:T,T:] by FUNCT_2:66;
assume A77:
SumFTS9 . [p,q] < 1
;
contradiction
reconsider FnB =
Fn . B as
RealMap of
T by A67, FUNCT_2:5, FUNCT_2:66;
A78:
FnB in Funcs ( the
carrier of
T,
REAL)
by A67, FUNCT_2:5;
q in B `
by A70, XBOOLE_0:def 5;
then A79:
FnB . q = 0
by A71;
x = p
by A75, XTUPLE_0:1;
then
FnB in H3(
x)
by A67, A74;
then
FnB in H3(
x)
\/ H3(
y)
by XBOOLE_0:def 3;
then A80:
Fdist . FnB in rng SF
by A76;
then reconsider FdistFnB =
Fdist . FnB as
RealMap of
[:T,T:] by FUNCT_2:66;
SF <> {}
by A80, RELAT_1:38;
then
len SF >= 1
by NAT_1:14;
then consider F being
sequence of
(Funcs ( the carrier of [:T,T:],REAL)) such that A81:
F . 1
= SF . 1
and A82:
for
n being
Nat st
0 <> n &
n < len SF holds
F . (n + 1) = ADD . (
(F . n),
(SF . (n + 1)))
and A83:
ADD "**" SF = F . (len SF)
by FINSOP_1:def 1;
A84:
(
SumFTS . pq = (SumFdist . pq) . pq &
SumFdist . pq = ASF )
by A63, NAGATA_1:def 8;
defpred S10[
Nat]
means for
k being
Nat st
k <> 0 &
k <= $1 & $1
<= len SF holds
for
fk,
Fn being
RealMap of
[:T,T:] st
fk = SF . k &
Fn = F . $1 holds
fk . pq <= Fn . pq;
A85:
for
k being
Nat st
k <> 0 &
k <= len SF holds
for
f being
RealMap of
[:T,T:] st
f = SF . k holds
f . pq >= 0
proof
let k be
Nat;
( k <> 0 & k <= len SF implies for f being RealMap of [:T,T:] st f = SF . k holds
f . pq >= 0 )
assume that A86:
k <> 0
and A87:
k <= len SF
;
for f being RealMap of [:T,T:] st f = SF . k holds
f . pq >= 0
k >= 1
by A86, NAT_1:14;
then
k in dom SF
by A87, FINSEQ_3:25;
then
SF . k in H4(
H3(
x)
\/ H3(
y))
by A76, FUNCT_1:def 3;
then consider fd being
RealMap of
T such that A88:
Fdist . fd = SF . k
and
fd in H3(
x)
\/ H3(
y)
;
let f be
RealMap of
[:T,T:];
( f = SF . k implies f . pq >= 0 )
assume A89:
f = SF . k
;
f . pq >= 0
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
then
f . (
p,
q)
= |.((fd . p) - (fd . q)).|
by A46, A89, A88;
hence
f . pq >= 0
by COMPLEX1:46;
verum
end;
A90:
for
i being
Nat st
S10[
i] holds
S10[
i + 1]
proof
let i be
Nat;
( S10[i] implies S10[i + 1] )
assume A91:
S10[
i]
;
S10[i + 1]
let k be
Nat;
( k <> 0 & k <= i + 1 & i + 1 <= len SF implies for fk, Fn being RealMap of [:T,T:] st fk = SF . k & Fn = F . (i + 1) holds
fk . pq <= Fn . pq )
assume that A92:
k <> 0
and A93:
k <= i + 1
and A94:
i + 1
<= len SF
;
for fk, Fn being RealMap of [:T,T:] st fk = SF . k & Fn = F . (i + 1) holds
fk . pq <= Fn . pq
now for fk, Fn being RealMap of [:T,T:] st fk = SF . k & Fn = F . (i + 1) holds
fk . pq <= Fn . pq
1
<= i + 1
by NAT_1:14;
then
i + 1
in dom SF
by A94, FINSEQ_3:25;
then
SF . (i + 1) in rng SF
by FUNCT_1:def 3;
then reconsider SFi1 =
SF . (i + 1) as
RealMap of
[:T,T:] by FUNCT_2:66;
reconsider Fi =
F . i as
RealMap of
[:T,T:] by FUNCT_2:66;
let fk,
Fn be
RealMap of
[:T,T:];
( fk = SF . k & Fn = F . (i + 1) implies b1 . pq <= b2 . pq )assume that A95:
fk = SF . k
and A96:
Fn = F . (i + 1)
;
b1 . pq <= b2 . pqper cases
( k < i + 1 or k = i + 1 )
by A93, XXREAL_0:1;
suppose A97:
k < i + 1
;
b1 . pq <= b2 . pqA98:
i < len SF
by A94, NAT_1:13;
i <> 0
by A92, A97, NAT_1:13;
then
F . (i + 1) = ADD . (
(F . i),
(SF . (i + 1)))
by A82, A98;
then A99:
Fn = Fi + SFi1
by A64, A96;
SFi1 . pq >= 0
by A85, A94;
then
(Fi . pq) + 0 <= (Fi . pq) + (SFi1 . pq)
by XREAL_1:7;
then A100:
Fn . pq >= Fi . pq
by A99, NAGATA_1:def 7;
A101:
i <= len SF
by A94, NAT_1:13;
k <= i
by A97, NAT_1:13;
then
fk . pq <= Fi . pq
by A91, A92, A95, A101;
hence
fk . pq <= Fn . pq
by A100, XXREAL_0:2;
verum end; suppose A102:
k = i + 1
;
b1 . pq <= b2 . pqper cases
( i = 0 or i <> 0 )
;
suppose A103:
i <> 0
;
b1 . pq <= b2 . pq
i + 0 < i + 1
by XREAL_1:8;
then A104:
i < len SF
by A94, XXREAL_0:2;
1
<= i
by A103, NAT_1:14;
then
i in dom SF
by A104, FINSEQ_3:25;
then
SF . i in rng SF
by FUNCT_1:def 3;
then reconsider SFi =
SF . i as
RealMap of
[:T,T:] by FUNCT_2:66;
0 <= SFi . pq
by A85, A103, A104;
then
0 <= Fi . pq
by A91, A103, A104;
then A105:
(Fi . pq) + (fk . pq) >= 0 + (fk . pq)
by XREAL_1:7;
F . (i + 1) = ADD . (
(F . i),
(SF . (i + 1)))
by A82, A103, A104;
then
Fn = Fi + fk
by A64, A95, A96, A102;
hence
fk . pq <= Fn . pq
by A105, NAGATA_1:def 7;
verum end; end; end; end; end;
hence
for
fk,
Fn being
RealMap of
[:T,T:] st
fk = SF . k &
Fn = F . (i + 1) holds
fk . pq <= Fn . pq
;
verum
end;
A106:
S10[
0 ]
;
A107:
for
i being
Nat holds
S10[
i]
from NAT_1:sch 2(A106, A90);
consider k being
object such that A108:
k in dom SF
and A109:
SF . k = Fdist . FnB
by A80, FUNCT_1:def 3;
A110:
k in Seg (len SF)
by A108, FINSEQ_1:def 3;
FnB . p = 1
by A73, A71;
then A111:
FdistFnB . (
p,
q)
= |.(1 - 0).|
by A46, A78, A79;
reconsider k =
k as
Element of
NAT by A108;
A112:
|.1.| = 1
by ABSVALUE:def 1;
(
k <> 0 &
k <= len SF )
by A110, FINSEQ_1:1;
hence
contradiction
by A77, A84, A83, A107, A111, A112, A109;
verum
end;
A113:
now for p, q being Point of T st ex A, B being Subset of T st
( A is open & B is open & A in Bn . m & B in Bn . n & p in A & Cl A c= B & not q in B ) holds
1 = (min (jj,SumFTS9)) . [p,q]let p,
q be
Point of
T;
( ex A, B being Subset of T st
( A is open & B is open & A in Bn . m & B in Bn . n & p in A & Cl A c= B & not q in B ) implies 1 = (min (jj,SumFTS9)) . [p,q] )assume
ex
A,
B being
Subset of
T st
(
A is
open &
B is
open &
A in Bn . m &
B in Bn . n &
p in A &
Cl A c= B & not
q in B )
;
1 = (min (jj,SumFTS9)) . [p,q]then
SumFTS9 . [p,q] >= 1
by A65;
then A114:
1
= min (1,
(SumFTS9 . [p,q]))
by XXREAL_0:def 9;
[: the carrier of T, the carrier of T:] = the
carrier of
[:T,T:]
by BORSUK_1:def 2;
hence
1
= (min (jj,SumFTS9)) . [p,q]
by A114, NAGATA_1:def 9;
verum end;
A115:
for
pq being
Element of the
carrier of
[:T,T:] for
map9 being
Element of
Funcs ( the
carrier of
[:T,T:],
REAL) st
map9 is_a_unity_wrt ADD holds
map9 . pq = 0
A116:
for
pq1,
pq2 being
Point of
[:T,T:] holds
( (
pq1 in SS . pq2 implies
(SumFdist . pq1) . pq1 = (SumFdist . pq2) . pq1 ) & ( for
SumFdist1,
SumFdist2 being
RealMap of
[:T,T:] st
SumFdist1 = SumFdist . pq1 &
SumFdist2 = SumFdist . pq2 holds
SumFdist1 . pq1 >= SumFdist2 . pq1 ) )
proof
deffunc H5(
Element of
T,
Element of
T)
-> set =
{ (Fn . A) where A is Subset of T : ( A in Bn . n & ( for FnA being RealMap of T holds
( not Fn . A = FnA or FnA . $1 > 0 or FnA . $2 > 0 ) ) ) } ;
let pq1,
pq2 be
Point of
[:T,T:];
( ( pq1 in SS . pq2 implies (SumFdist . pq1) . pq1 = (SumFdist . pq2) . pq1 ) & ( for SumFdist1, SumFdist2 being RealMap of [:T,T:] st SumFdist1 = SumFdist . pq1 & SumFdist2 = SumFdist . pq2 holds
SumFdist1 . pq1 >= SumFdist2 . pq1 ) )
reconsider S1 =
SFdist . pq1,
S2 =
SFdist . pq2 as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by FINSEQ_1:def 11;
consider p1,
q1 being
Point of
T such that A117:
[p1,q1] = pq1
and A118:
rng S1 = H4(
H3(
p1)
\/ H3(
q1))
by A61;
A119:
for
p,
q,
p1,
q1 being
Point of
T st
[p,q] in SS . [p1,q1] holds
H5(
p,
q)
c= H3(
p1)
\/ H3(
q1)
proof
let p,
q,
p1,
q1 be
Point of
T;
( [p,q] in SS . [p1,q1] implies H5(p,q) c= H3(p1) \/ H3(q1) )
assume A120:
[p,q] in SS . [p1,q1]
;
H5(p,q) c= H3(p1) \/ H3(q1)
reconsider pq1 =
[p1,q1] as
Element of the
carrier of
[:T,T:] by BORSUK_1:def 2;
[:(Sx . p1),(Sx . q1):] = SS . pq1
by A34;
then A121:
(
p in Sx . p1 &
q in Sx . q1 )
by A120, ZFMISC_1:87;
let no0 be
object ;
TARSKI:def 3 ( not no0 in H5(p,q) or no0 in H3(p1) \/ H3(q1) )
assume
no0 in H5(
p,
q)
;
no0 in H3(p1) \/ H3(q1)
then consider A being
Subset of
T such that A122:
no0 = Fn . A
and A123:
A in Bn . n
and A124:
for
FnA being
RealMap of
T holds
( not
Fn . A = FnA or
FnA . p > 0 or
FnA . q > 0 )
;
reconsider FnA =
Fn . A as
RealMap of
T by A123, FUNCT_2:5, FUNCT_2:66;
A125:
(
FnA . p > 0 or
FnA . q > 0 )
by A124;
S6[
A,
Fn . A]
by A26, A123;
then
( not
p in the
carrier of
T \ A or not
q in the
carrier of
T \ A )
by A125;
then
(
p in A or
q in A )
by XBOOLE_0:def 5;
then
(
A meets Sx . p1 or
A meets Sx . q1 )
by A121, XBOOLE_0:3;
then
(
A in H2(
Sx . p1) or
A in H2(
Sx . q1) )
by A123;
then
(
FnA in H3(
p1) or
FnA in H3(
q1) )
by A123;
hence
no0 in H3(
p1)
\/ H3(
q1)
by A122, XBOOLE_0:def 3;
verum
end;
A126:
H4(
H5(
p1,
q1))
c= H4(
H3(
p1)
\/ H3(
q1))
A128:
for
f being
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
for
p,
q,
p1,
q1 being
Point of
T st
rng f = H4(
H3(
p1)
\/ H3(
q1))
\ H4(
H5(
p,
q)) holds
(ADD "**" f) . [p,q] = 0
proof
let f be
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL);
for p, q, p1, q1 being Point of T st rng f = H4(H3(p1) \/ H3(q1)) \ H4(H5(p,q)) holds
(ADD "**" f) . [p,q] = 0 let p,
q,
p1,
q1 be
Point of
T;
( rng f = H4(H3(p1) \/ H3(q1)) \ H4(H5(p,q)) implies (ADD "**" f) . [p,q] = 0 )
assume A129:
rng f = H4(
H3(
p1)
\/ H3(
q1))
\ H4(
H5(
p,
q))
;
(ADD "**" f) . [p,q] = 0
reconsider pq =
[p,q] as
Element of the
carrier of
[:T,T:] by BORSUK_1:def 2;
now (ADD "**" f) . pq = 0 per cases
( len f = 0 or len f <> 0 )
;
suppose A133:
len f <> 0
;
(ADD "**" f) . pq = 0 then
len f >= 1
by NAT_1:14;
then consider F being
sequence of
(Funcs ( the carrier of [:T,T:],REAL)) such that A134:
F . 1
= f . 1
and A135:
for
n being
Nat st
0 <> n &
n < len f holds
F . (n + 1) = ADD . (
(F . n),
(f . (n + 1)))
and A136:
ADD "**" f = F . (len f)
by FINSOP_1:def 1;
defpred S10[
Nat]
means ( $1
<> 0 & $1
<= len f implies
(F . $1) . pq = 0 );
A137:
for
k being
Nat st
S10[
k] holds
S10[
k + 1]
proof
let k be
Nat;
( S10[k] implies S10[k + 1] )
assume A138:
S10[
k]
;
S10[k + 1]
assume that
k + 1
<> 0
and A139:
k + 1
<= len f
;
(F . (k + 1)) . pq = 0
A140:
k < len f
by A139, NAT_1:13;
k + 1
>= 1
by NAT_1:14;
then
k + 1
in dom f
by A139, FINSEQ_3:25;
then A141:
f . (k + 1) in H4(
H3(
p1)
\/ H3(
q1))
\ H4(
H5(
p,
q))
by A129, FUNCT_1:def 3;
then
f . (k + 1) in H4(
H3(
p1)
\/ H3(
q1))
;
then consider fd being
RealMap of
T such that A142:
Fdist . fd = f . (k + 1)
and A143:
fd in H3(
p1)
\/ H3(
q1)
;
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
then reconsider Fdistfd =
Fdist . fd,
Fk1 =
F . (k + 1),
Fk =
F . k,
fk1 =
f . (k + 1) as
RealMap of
[:T,T:] by A142, FUNCT_2:5, FUNCT_2:66;
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
then A144:
Fdistfd . (
p,
q)
= |.((fd . p) - (fd . q)).|
by A46;
A145:
not
f . (k + 1) in H4(
H5(
p,
q))
by A141, XBOOLE_0:def 5;
A146:
(
fd . p = 0 &
fd . q = 0 )
proof
assume A147:
(
fd . p <> 0 or
fd . q <> 0 )
;
contradiction
end;
end; A155:
S10[
0 ]
;
for
n being
Nat holds
S10[
n]
from NAT_1:sch 2(A155, A137);
hence
(ADD "**" f) . pq = 0
by A133, A136;
verum end; end; end;
hence
(ADD "**" f) . [p,q] = 0
;
verum
end;
A156:
H4(
H3(
p1)
\/ H3(
q1)) is
finite
by A50;
then consider No being
FinSequence such that A157:
rng No = H4(
H5(
p1,
q1))
and A158:
No is
one-to-one
by A126, FINSEQ_4:58;
H4(
H3(
p1)
\/ H3(
q1))
c= Funcs ( the
carrier of
[:T,T:],
REAL)
by A50;
then A159:
H4(
H5(
p1,
q1))
c= Funcs ( the
carrier of
[:T,T:],
REAL)
by A126;
then reconsider No =
No as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by A157, FINSEQ_1:def 4;
consider p2,
q2 being
Point of
T such that A160:
[p2,q2] = pq2
and A161:
rng S2 = H4(
H3(
p2)
\/ H3(
q2))
by A61;
reconsider S1 =
SFdist . pq1,
S2 =
SFdist . pq2 as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by FINSEQ_1:def 11;
set RNiS2 =
H4(
H5(
p1,
q1))
/\ H4(
H3(
p2)
\/ H3(
q2));
A162:
S2 is
one-to-one
by A61;
A163:
(
ADD is
having_a_unity &
ADD is
commutative &
ADD is
associative )
by A64, NAGATA_1:23;
S1 is
one-to-one
by A61;
then consider S1No being
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
such that
S1No is
one-to-one
and A164:
rng S1No = (rng S1) \ (rng No)
and A165:
ADD "**" S1 = ADD . (
(ADD "**" No),
(ADD "**" S1No))
by A118, A126, A157, A158, A163, Th18;
consider NoiS2 being
FinSequence such that A166:
rng NoiS2 = H4(
H5(
p1,
q1))
/\ H4(
H3(
p2)
\/ H3(
q2))
and A167:
NoiS2 is
one-to-one
by A126, A156, FINSEQ_4:58;
H4(
H5(
p1,
q1))
/\ H4(
H3(
p2)
\/ H3(
q2))
c= H4(
H5(
p1,
q1))
by XBOOLE_1:17;
then
H4(
H5(
p1,
q1))
/\ H4(
H3(
p2)
\/ H3(
q2))
c= Funcs ( the
carrier of
[:T,T:],
REAL)
by A159;
then reconsider NoiS2 =
NoiS2 as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by A166, FINSEQ_1:def 4;
rng NoiS2 c= rng No
by A157, A166, XBOOLE_1:17;
then consider NoNoiS2 being
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
such that
NoNoiS2 is
one-to-one
and A168:
rng NoNoiS2 = (rng No) \ (rng NoiS2)
and A169:
ADD "**" No = ADD . (
(ADD "**" NoiS2),
(ADD "**" NoNoiS2))
by A158, A163, A167, Th18;
rng NoiS2 c= rng S2
by A161, A166, XBOOLE_1:17;
then consider S2No being
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
such that
S2No is
one-to-one
and A170:
rng S2No = (rng S2) \ (rng NoiS2)
and A171:
ADD "**" S2 = ADD . (
(ADD "**" NoiS2),
(ADD "**" S2No))
by A163, A167, A162, Th18;
reconsider ANoNoiS2 =
ADD "**" NoNoiS2,
ANo =
ADD "**" No,
AS1No =
ADD "**" S1No,
AS2No =
ADD "**" S2No,
ANoiS2 =
ADD "**" NoiS2,
AS1 =
ADD "**" S1,
AS2 =
ADD "**" S2 as
RealMap of
[:T,T:] by FUNCT_2:66;
rng S2No = H4(
H3(
p2)
\/ H3(
q2))
\ H4(
H5(
p1,
q1))
by A161, A166, A170, XBOOLE_1:47;
then A172:
AS2No . pq1 = 0
by A128, A117;
ANo = ANoiS2 + ANoNoiS2
by A64, A169;
then A173:
ANo . pq1 = (ANoiS2 . pq1) + (ANoNoiS2 . pq1)
by NAGATA_1:def 7;
AS1 = ANo + AS1No
by A64, A165;
then A174:
AS1 . pq1 = (ANo . pq1) + (AS1No . pq1)
by NAGATA_1:def 7;
AS2 = ANoiS2 + AS2No
by A64, A171;
then A175:
AS2 . pq1 = (ANoiS2 . pq1) + (AS2No . pq1)
by NAGATA_1:def 7;
A176:
AS1No . pq1 = 0
by A128, A117, A118, A157, A164;
thus
(
pq1 in SS . pq2 implies
(SumFdist . pq1) . pq1 = (SumFdist . pq2) . pq1 )
for SumFdist1, SumFdist2 being RealMap of [:T,T:] st SumFdist1 = SumFdist . pq1 & SumFdist2 = SumFdist . pq2 holds
SumFdist1 . pq1 >= SumFdist2 . pq1proof
A177:
ADD is
having_a_unity
by A64, NAGATA_1:23;
then A178:
ex
f being
Element of
Funcs ( the
carrier of
[:T,T:],
REAL) st
f is_a_unity_wrt ADD
by SETWISEO:def 2;
assume A179:
pq1 in SS . pq2
;
(SumFdist . pq1) . pq1 = (SumFdist . pq2) . pq1
now for FD being object st FD in H4(H5(p1,q1)) holds
FD in H4(H3(p2) \/ H3(q2))let FD be
object ;
( FD in H4(H5(p1,q1)) implies FD in H4(H3(p2) \/ H3(q2)) )assume
FD in H4(
H5(
p1,
q1))
;
FD in H4(H3(p2) \/ H3(q2))then A180:
ex
fd being
RealMap of
T st
(
FD = Fdist . fd &
fd in H5(
p1,
q1) )
;
H5(
p1,
q1)
c= H3(
p2)
\/ H3(
q2)
by A119, A117, A160, A179;
hence
FD in H4(
H3(
p2)
\/ H3(
q2))
by A180;
verum end;
then
H4(
H5(
p1,
q1))
c= H4(
H3(
p2)
\/ H3(
q2))
;
then
H4(
H5(
p1,
q1))
/\ H4(
H3(
p2)
\/ H3(
q2))
= H4(
H5(
p1,
q1))
by XBOOLE_1:28;
then
rng NoNoiS2 = {}
by A157, A166, A168, XBOOLE_1:37;
then
NoNoiS2 = {}
by RELAT_1:41;
then
len NoNoiS2 = 0
;
then
ADD "**" NoNoiS2 = the_unity_wrt ADD
by A177, FINSOP_1:def 1;
then
ADD "**" NoNoiS2 is_a_unity_wrt ADD
by A178, BINOP_1:def 8;
then A181:
AS1 . pq1 = AS2 . pq1
by A115, A174, A173, A175, A176, A172;
SumFdist . pq1 = AS1
by A63;
hence
(SumFdist . pq1) . pq1 = (SumFdist . pq2) . pq1
by A63, A181;
verum
end;
A182:
ANoNoiS2 . (
p1,
q1)
>= 0
proof
set N =
NoNoiS2;
per cases
( len NoNoiS2 = 0 or len NoNoiS2 <> 0 )
;
suppose A186:
len NoNoiS2 <> 0
;
ANoNoiS2 . (p1,q1) >= 0 then
len NoNoiS2 >= 1
by NAT_1:14;
then consider F being
sequence of
(Funcs ( the carrier of [:T,T:],REAL)) such that A187:
F . 1
= NoNoiS2 . 1
and A188:
for
n being
Nat st
0 <> n &
n < len NoNoiS2 holds
F . (n + 1) = ADD . (
(F . n),
(NoNoiS2 . (n + 1)))
and A189:
ADD "**" NoNoiS2 = F . (len NoNoiS2)
by FINSOP_1:def 1;
defpred S10[
Nat]
means ( $1
<> 0 & $1
<= len NoNoiS2 implies for
Fn being
RealMap of
[:T,T:] st
Fn = F . $1 holds
Fn . (
p1,
q1)
>= 0 );
A190:
for
k being
Nat st
S10[
k] holds
S10[
k + 1]
proof
let k be
Nat;
( S10[k] implies S10[k + 1] )
assume A191:
S10[
k]
;
S10[k + 1]
assume that
k + 1
<> 0
and A192:
k + 1
<= len NoNoiS2
;
for Fn being RealMap of [:T,T:] st Fn = F . (k + 1) holds
Fn . (p1,q1) >= 0
A193:
k < len NoNoiS2
by A192, NAT_1:13;
k + 1
>= 1
by NAT_1:14;
then
k + 1
in dom NoNoiS2
by A192, FINSEQ_3:25;
then
NoNoiS2 . (k + 1) in (rng No) \ (rng NoiS2)
by A168, FUNCT_1:def 3;
then
NoNoiS2 . (k + 1) in H4(
H5(
p1,
q1))
by A157, XBOOLE_0:def 5;
then consider fd being
RealMap of
T such that A194:
Fdist . fd = NoNoiS2 . (k + 1)
and
fd in H5(
p1,
q1)
;
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
then reconsider Fdistfd =
Fdist . fd,
Fk1 =
F . (k + 1),
Fk =
F . k,
Nk1 =
NoNoiS2 . (k + 1) as
RealMap of
[:T,T:] by A194, FUNCT_2:5, FUNCT_2:66;
A195:
|.((fd . p1) - (fd . q1)).| >= 0
by COMPLEX1:46;
A196:
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
then A197:
Fdistfd . (
p1,
q1)
= |.((fd . p1) - (fd . q1)).|
by A46;
A198:
now Fk1 . (p1,q1) >= 0 per cases
( k = 0 or k > 0 )
;
suppose A199:
k > 0
;
Fk1 . (p1,q1) >= 0
Fk1 = ADD . (
Fk,
Nk1)
by A188, A193, A199;
then A200:
Fk1 = Fk + Nk1
by A64;
Fk . (
p1,
q1)
>= 0
by A191, A192, A199, NAT_1:13;
then
0 + 0 <= (Fk . (p1,q1)) + (Nk1 . (p1,q1))
by A194, A195, A197;
hence
Fk1 . (
p1,
q1)
>= 0
by A117, A200, NAGATA_1:def 7;
verum end; end; end;
let Fn be
RealMap of
[:T,T:];
( Fn = F . (k + 1) implies Fn . (p1,q1) >= 0 )
assume
Fn = F . (k + 1)
;
Fn . (p1,q1) >= 0
hence
Fn . (
p1,
q1)
>= 0
by A198;
verum
end; A201:
S10[
0 ]
;
for
n being
Nat holds
S10[
n]
from NAT_1:sch 2(A201, A190);
hence
ANoNoiS2 . (
p1,
q1)
>= 0
by A186, A189;
verum end; end;
end;
now for SumFdist1, SumFdist2 being RealMap of [:T,T:] st SumFdist1 = SumFdist . pq1 & SumFdist2 = SumFdist . pq2 holds
SumFdist1 . pq1 >= SumFdist2 . pq1A202:
AS2 . (
p1,
q1)
<= AS1 . (
p1,
q1)
by A117, A182, A174, A173, A175, A176, A172, XREAL_1:7;
let SumFdist1,
SumFdist2 be
RealMap of
[:T,T:];
( SumFdist1 = SumFdist . pq1 & SumFdist2 = SumFdist . pq2 implies SumFdist1 . pq1 >= SumFdist2 . pq1 )assume that A203:
SumFdist1 = SumFdist . pq1
and A204:
SumFdist2 = SumFdist . pq2
;
SumFdist1 . pq1 >= SumFdist2 . pq1
SumFdist2 = AS2
by A63, A204;
hence
SumFdist1 . pq1 >= SumFdist2 . pq1
by A63, A117, A203, A202;
verum end;
hence
for
SumFdist1,
SumFdist2 being
RealMap of
[:T,T:] st
SumFdist1 = SumFdist . pq1 &
SumFdist2 = SumFdist . pq2 holds
SumFdist1 . pq1 >= SumFdist2 . pq1
;
verum
end;
now for p, q, r being Point of T holds
( SumFTS . (p,p) = 0 & SumFTS . (p,r) <= (SumFTS . (p,q)) + (SumFTS . (r,q)) )let p,
q,
r be
Point of
T;
( SumFTS . (p,p) = 0 & SumFTS . (p,r) <= (SumFTS . (p,q)) + (SumFTS . (r,q)) )thus
SumFTS . (
p,
p)
= 0
SumFTS . (p,r) <= (SumFTS . (p,q)) + (SumFTS . (r,q))proof
reconsider pp =
[p,p] as
Point of
[:T,T:] by BORSUK_1:def 2;
reconsider SF =
SFdist . pp as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by FINSEQ_1:def 11;
A205:
now (ADD "**" SF) . pp = 0 per cases
( len SF = 0 or len SF <> 0 )
;
suppose A209:
len SF <> 0
;
(ADD "**" SF) . pp = 0 then
len SF >= 1
by NAT_1:14;
then consider F being
sequence of
(Funcs ( the carrier of [:T,T:],REAL)) such that A210:
F . 1
= SF . 1
and A211:
for
n being
Nat st
0 <> n &
n < len SF holds
F . (n + 1) = ADD . (
(F . n),
(SF . (n + 1)))
and A212:
ADD "**" SF = F . (len SF)
by FINSOP_1:def 1;
defpred S10[
Nat]
means ( $1
<> 0 & $1
<= len SF implies
(F . $1) . pp = 0 );
A213:
for
k being
Nat st
S10[
k] holds
S10[
k + 1]
proof
let k be
Nat;
( S10[k] implies S10[k + 1] )
assume A214:
S10[
k]
;
S10[k + 1]
consider x,
y being
Point of
T such that
[x,y] = pp
and A215:
rng SF = H4(
H3(
x)
\/ H3(
y))
by A61;
assume that
k + 1
<> 0
and A216:
k + 1
<= len SF
;
(F . (k + 1)) . pp = 0
A217:
k < len SF
by A216, NAT_1:13;
k + 1
>= 1
by NAT_1:14;
then
k + 1
in dom SF
by A216, FINSEQ_3:25;
then
SF . (k + 1) in H4(
H3(
x)
\/ H3(
y))
by A215, FUNCT_1:def 3;
then consider fd being
RealMap of
T such that A218:
Fdist . fd = SF . (k + 1)
and
fd in H3(
x)
\/ H3(
y)
;
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
then reconsider Fdistfd =
Fdist . fd,
Fk1 =
F . (k + 1),
Fk =
F . k,
SFk1 =
SF . (k + 1) as
RealMap of
[:T,T:] by A218, FUNCT_2:5, FUNCT_2:66;
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
then A219:
Fdistfd . (
p,
p)
= |.((fd . p) - (fd . p)).|
by A46;
end; A221:
S10[
0 ]
;
for
n being
Nat holds
S10[
n]
from NAT_1:sch 2(A221, A213);
hence
(ADD "**" SF) . pp = 0
by A209, A212;
verum end; end; end;
SumFdist . pp = ADD "**" SF
by A63;
hence
SumFTS . (
p,
p)
= 0
by A205, NAGATA_1:def 8;
verum
end; thus
SumFTS . (
p,
r)
<= (SumFTS . (p,q)) + (SumFTS . (r,q))
verumproof
reconsider pr =
[p,r],
pq =
[p,q],
rq =
[r,q] as
Point of
[:T,T:] by BORSUK_1:def 2;
reconsider SFpr =
SFdist . pr as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by FINSEQ_1:def 11;
reconsider ASFpr =
ADD "**" SFpr as
RealMap of
[:T,T:] by FUNCT_2:66;
reconsider SumFpr =
SumFdist . pr,
SumFpq =
SumFdist . pq,
SumFrq =
SumFdist . rq as
RealMap of
[:T,T:] by FUNCT_2:66;
A222:
(
SumFTS . pr = SumFpr . pr &
SumFTS . pq = SumFpq . pq )
by NAGATA_1:def 8;
(
SumFpr . pq <= SumFpq . pq &
SumFpr . rq <= SumFrq . rq )
by A116;
then A223:
(SumFpr . pq) + (SumFpr . rq) <= (SumFpq . pq) + (SumFrq . rq)
by XREAL_1:7;
A224:
now ASFpr . pr <= (ASFpr . pq) + (ASFpr . rq)per cases
( len SFpr = 0 or len SFpr <> 0 )
;
suppose A229:
len SFpr <> 0
;
ASFpr . pr <= (ASFpr . pq) + (ASFpr . rq)then
len SFpr >= 1
by NAT_1:14;
then consider F being
sequence of
(Funcs ( the carrier of [:T,T:],REAL)) such that A230:
F . 1
= SFpr . 1
and A231:
for
n being
Nat st
0 <> n &
n < len SFpr holds
F . (n + 1) = ADD . (
(F . n),
(SFpr . (n + 1)))
and A232:
ADD "**" SFpr = F . (len SFpr)
by FINSOP_1:def 1;
defpred S10[
Nat]
means ( $1
<> 0 & $1
<= len SFpr implies for
F9 being
RealMap of
[:T,T:] st
F9 = F . $1 holds
F9 . pr <= (F9 . pq) + (F9 . rq) );
A233:
for
k being
Nat st
S10[
k] holds
S10[
k + 1]
proof
let k be
Nat;
( S10[k] implies S10[k + 1] )
assume A234:
S10[
k]
;
S10[k + 1]
consider x,
y being
Point of
T such that
[x,y] = pr
and A235:
rng SFpr = H4(
H3(
x)
\/ H3(
y))
by A61;
assume that
k + 1
<> 0
and A236:
k + 1
<= len SFpr
;
for F9 being RealMap of [:T,T:] st F9 = F . (k + 1) holds
F9 . pr <= (F9 . pq) + (F9 . rq)
A237:
k < len SFpr
by A236, NAT_1:13;
k + 1
>= 1
by NAT_1:14;
then
k + 1
in dom SFpr
by A236, FINSEQ_3:25;
then
SFpr . (k + 1) in H4(
H3(
x)
\/ H3(
y))
by A235, FUNCT_1:def 3;
then consider fd being
RealMap of
T such that A238:
Fdist . fd = SFpr . (k + 1)
and
fd in H3(
x)
\/ H3(
y)
;
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
then reconsider Fdistfd =
Fdist . fd,
Fk1 =
F . (k + 1),
Fk =
F . k,
SFk1 =
SFpr . (k + 1) as
RealMap of
[:T,T:] by A238, FUNCT_2:5, FUNCT_2:66;
A239:
(fd . p) - (fd . r) = ((fd . p) - (fd . q)) + ((fd . q) - (fd . r))
;
then A240:
|.((fd . p) - (fd . r)).| <= |.((fd . p) - (fd . q)).| + |.((fd . q) - (fd . r)).|
by COMPLEX1:56;
A241:
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
then A242:
(
Fdistfd . (
p,
r)
= |.((fd . p) - (fd . r)).| &
Fdistfd . (
p,
q)
= |.((fd . p) - (fd . q)).| )
by A46;
A243:
(
|.((fd . q) - (fd . r)).| = |.(- ((fd . q) - (fd . r))).| &
Fdistfd . (
r,
q)
= |.((fd . r) - (fd . q)).| )
by A46, A241, COMPLEX1:52;
let F9 be
RealMap of
[:T,T:];
( F9 = F . (k + 1) implies F9 . pr <= (F9 . pq) + (F9 . rq) )
assume A244:
F9 = F . (k + 1)
;
F9 . pr <= (F9 . pq) + (F9 . rq)
per cases
( k = 0 or k > 0 )
;
suppose A245:
k > 0
;
F9 . pr <= (F9 . pq) + (F9 . rq)then
Fk . pr <= (Fk . pq) + (Fk . rq)
by A234, A236, NAT_1:13;
then A246:
(Fk . pr) + (SFk1 . pr) <= ((Fk . pq) + (Fk . rq)) + ((SFk1 . pq) + (SFk1 . rq))
by A238, A240, A242, A243, XREAL_1:7;
Fk1 = ADD . (
Fk,
SFk1)
by A231, A237, A245;
then A247:
Fk1 = Fk + SFk1
by A64;
then
(
Fk1 . pq = (Fk . pq) + (SFk1 . pq) &
Fk1 . rq = (Fk . rq) + (SFk1 . rq) )
by NAGATA_1:def 7;
hence
F9 . pr <= (F9 . pq) + (F9 . rq)
by A244, A247, A246, NAGATA_1:def 7;
verum end; end;
end; A248:
S10[
0 ]
;
for
n being
Nat holds
S10[
n]
from NAT_1:sch 2(A248, A233);
hence
ASFpr . pr <= (ASFpr . pq) + (ASFpr . rq)
by A229, A232;
verum end; end; end;
SumFpr = ADD "**" SFpr
by A63;
then
SumFpr . pr <= (SumFpq . pq) + (SumFrq . rq)
by A224, A223, XXREAL_0:2;
hence
SumFTS . (
p,
r)
<= (SumFTS . (p,q)) + (SumFTS . (r,q))
by A222, NAGATA_1:def 8;
verum
end; end;
then A249:
SumFTS is_a_pseudometric_of the
carrier of
T
by NAGATA_1:28;
A250:
for
p being
Point of
T for
fd being
Element of
Funcs ( the
carrier of
T,
REAL) st
fd in H3(
p) holds
(
S4[
fd,
Fdist . fd] &
Fdist . fd is
continuous RealMap of
[:T,T:] )
proof
let p be
Point of
T;
for fd being Element of Funcs ( the carrier of T,REAL) st fd in H3(p) holds
( S4[fd,Fdist . fd] & Fdist . fd is continuous RealMap of [:T,T:] )let fd be
Element of
Funcs ( the
carrier of
T,
REAL);
( fd in H3(p) implies ( S4[fd,Fdist . fd] & Fdist . fd is continuous RealMap of [:T,T:] ) )
reconsider FD =
Fdist . fd as
RealMap of
[:T,T:] by FUNCT_2:66;
assume
fd in H3(
p)
;
( S4[fd,Fdist . fd] & Fdist . fd is continuous RealMap of [:T,T:] )
then consider A being
Subset of
T such that A251:
fd = Fn . A
and A252:
A in Bn . n
and
A in H2(
Sx . p)
;
A253:
S4[
fd,
Fdist . fd]
by A46;
S6[
A,
Fn . A]
by A26, A252;
then
FD is
continuous
by A251, A253, NAGATA_1:21;
hence
(
S4[
fd,
Fdist . fd] &
Fdist . fd is
continuous RealMap of
[:T,T:] )
by A46;
verum
end;
A254:
for
pq9 being
Point of
[:T,T:] holds
SumFdist . pq9 is
continuous RealMap of
[:T,T:]
proof
let pq9 be
Point of
[:T,T:];
SumFdist . pq9 is continuous RealMap of [:T,T:]
reconsider SF =
SFdist . pq9 as
FinSequence of
Funcs ( the
carrier of
[:T,T:],
REAL)
by FINSEQ_1:def 11;
consider p,
q being
Point of
T such that
[p,q] = pq9
and A255:
rng SF = H4(
H3(
p)
\/ H3(
q))
by A61;
for
n being
Element of
NAT st
0 <> n &
n <= len SF holds
SF . n is
continuous RealMap of
[:T,T:]
proof
let n be
Element of
NAT ;
( 0 <> n & n <= len SF implies SF . n is continuous RealMap of [:T,T:] )
assume that A256:
0 <> n
and A257:
n <= len SF
;
SF . n is continuous RealMap of [:T,T:]
n >= 1
by A256, NAT_1:14;
then
n in dom SF
by A257, FINSEQ_3:25;
then
SF . n in H4(
H3(
p)
\/ H3(
q))
by A255, FUNCT_1:def 3;
then consider fd being
RealMap of
T such that A258:
SF . n = Fdist . fd
and A259:
fd in H3(
p)
\/ H3(
q)
;
A260:
fd in Funcs ( the
carrier of
T,
REAL)
by FUNCT_2:8;
(
fd in H3(
p) or
fd in H3(
q) )
by A259, XBOOLE_0:def 3;
hence
SF . n is
continuous RealMap of
[:T,T:]
by A250, A258, A260;
verum
end;
then
ADD "**" SF is
continuous RealMap of
[:T,T:]
by A64, NAGATA_1:25;
hence
SumFdist . pq9 is
continuous RealMap of
[:T,T:]
by A63;
verum
end;
A261:
for
pq9 being
Point of
[:T,T:] holds
SumFdist9 . pq9 is
continuous Function of
[:T,T:],
R^1
take
min (
jj,
SumFTS9)
;
S1[n,m, min (jj,SumFTS9)]
A262:
for
p,
q being
Point of
T holds
(min (jj,SumFTS9)) . [p,q] <= 1
proof
let p,
q be
Point of
T;
(min (jj,SumFTS9)) . [p,q] <= 1
the
carrier of
[:T,T:] = [: the carrier of T, the carrier of T:]
by BORSUK_1:def 2;
then
(min (jj,SumFTS9)) . [p,q] = min (1,
(SumFTS9 . [p,q]))
by NAGATA_1:def 9;
hence
(min (jj,SumFTS9)) . [p,q] <= 1
by XXREAL_0:17;
verum
end;
for
p,
q being
Point of
[:T,T:] st
p in SS . q holds
(SumFdist9 . p) . p = (SumFdist9 . q) . p
by A116;
then
SumFdist9 Toler is
continuous
by A261, A35, NAGATA_1:26;
then
SumFTS9 is
continuous
by JORDAN5A:27;
then
(
min (
jj,
SumFTS9)
= min (
jj,
SumFTS) &
min (
jj,
SumFTS9) is
continuous )
by BORSUK_1:def 2, NAGATA_1:27;
hence
S1[
n,
m,
min (
jj,
SumFTS9)]
by A249, A262, A113, NAGATA_1:30;
verum
end;
A263:
for
k being
object st
k in NAT holds
ex
f being
object st
(
f in Funcs ( the
carrier of
[:T,T:],
REAL) &
S2[
k,
f] )
proof
A264:
NAT = rng PairFunc
by Th2, FUNCT_2:def 3;
let k be
object ;
( k in NAT implies ex f being object st
( f in Funcs ( the carrier of [:T,T:],REAL) & S2[k,f] ) )
assume
k in NAT
;
ex f being object st
( f in Funcs ( the carrier of [:T,T:],REAL) & S2[k,f] )
then consider nm being
object such that A265:
nm in dom PairFunc
and A266:
k = PairFunc . nm
by A264, FUNCT_1:def 3;
consider n,
m being
object such that A267:
(
n in NAT &
m in NAT )
and A268:
nm = [n,m]
by A265, ZFMISC_1:def 2;
consider pmet9 being
RealMap of
[:T,T:] such that A269:
S1[
n,
m,
pmet9]
by A7, A267;
take
pmet9
;
( pmet9 in Funcs ( the carrier of [:T,T:],REAL) & S2[k,pmet9] )
thus
pmet9 in Funcs ( the
carrier of
[:T,T:],
REAL)
by FUNCT_2:8;
S2[k,pmet9]
take pm =
pmet9;
( pm = pmet9 & ( for n, m being Nat st (PairFunc ") . k = [n,m] holds
S1[n,m,pm] ) )
thus
pm = pmet9
;
for n, m being Nat st (PairFunc ") . k = [n,m] holds
S1[n,m,pm]
let n1,
m1 be
Nat;
( (PairFunc ") . k = [n1,m1] implies S1[n1,m1,pm] )
assume
(PairFunc ") . k = [n1,m1]
;
S1[n1,m1,pm]
then
[n1,m1] = [n,m]
by A265, A266, A268, Lm2, Th2, FUNCT_1:32;
then
(
n1 = n &
m1 = m )
by XTUPLE_0:1;
hence
S1[
n1,
m1,
pm]
by A269;
verum
end;
consider F being
sequence of
(Funcs ( the carrier of [:T,T:],REAL)) such that A270:
for
n being
object st
n in NAT holds
S2[
n,
F . n]
from FUNCT_2:sch 1(A263);
dom F = NAT
by FUNCT_2:def 1;
then reconsider F9 =
F as
Functional_Sequence of
[: the carrier of T, the carrier of T:],
REAL by A271, SEQFUNC:1;
A272:
for
p being
Point of
T for
A9 being non
empty Subset of
T st not
p in A9 &
A9 is
closed holds
ex
k being
Nat st
for
pmet being
Function of
[: the carrier of T, the carrier of T:],
REAL st
F9 . k = pmet holds
(lower_bound (pmet,A9)) . p > 0
proof
let p be
Point of
T;
for A9 being non empty Subset of T st not p in A9 & A9 is closed holds
ex k being Nat st
for pmet being Function of [: the carrier of T, the carrier of T:],REAL st F9 . k = pmet holds
(lower_bound (pmet,A9)) . p > 0 let A9 be non
empty Subset of
T;
( not p in A9 & A9 is closed implies ex k being Nat st
for pmet being Function of [: the carrier of T, the carrier of T:],REAL st F9 . k = pmet holds
(lower_bound (pmet,A9)) . p > 0 )
assume that A273:
not
p in A9
and A274:
A9 is
closed
;
ex k being Nat st
for pmet being Function of [: the carrier of T, the carrier of T:],REAL st F9 . k = pmet holds
(lower_bound (pmet,A9)) . p > 0
set O =
A9 ` ;
p in A9 `
by A273, XBOOLE_0:def 5;
then consider U being
Subset of
T such that A275:
p in U
and A276:
Cl U c= A9 `
and A277:
U in Union Bn
by A1, A5, A274, NAGATA_1:19;
Union Bn c= the
topology of
T
by A5, TOPS_2:64;
then reconsider U =
U as
open Subset of
T by A277, PRE_TOPC:def 2;
consider n being
Nat such that A278:
U in Bn . n
by A277, PROB_1:12;
consider W being
Subset of
T such that A279:
(
p in W &
Cl W c= U )
and A280:
W in Union Bn
by A1, A5, A275, NAGATA_1:19;
Union Bn c= the
topology of
T
by A5, TOPS_2:64;
then reconsider W =
W as
open Subset of
T by A280, PRE_TOPC:def 2;
consider m being
Nat such that A281:
W in Bn . m
by A280, PROB_1:12;
set k =
PairFunc . [n,m];
A282:
PairFunc . [n,m] in NAT
by ORDINAL1:def 12;
A283:
(
n in NAT &
m in NAT )
by ORDINAL1:def 12;
consider G being
RealMap of
[:T,T:] such that A284:
G = F . (PairFunc . [n,m])
and A285:
for
n,
m being
Nat st
(PairFunc ") . (PairFunc . [n,m]) = [n,m] holds
S1[
n,
m,
G]
by A270, A282;
A286:
[n,m] in [:NAT,NAT:]
by A283, ZFMISC_1:87;
reconsider kk =
PairFunc . [n,m] as
Element of
NAT by ORDINAL1:def 12;
dom PairFunc = [:NAT,NAT:]
by FUNCT_2:def 1;
then
[n,m] = (PairFunc ") . kk
by Lm2, Th2, FUNCT_1:32, A286;
then consider pmet being
Function of
[: the carrier of T, the carrier of T:],
REAL such that A287:
G = pmet
and
G is
continuous
and
pmet is_a_pseudometric_of the
carrier of
T
and A288:
for
p,
q being
Point of
T holds
(
pmet . [p,q] <= 1 & ( for
p,
q being
Point of
T st ex
A,
B being
Subset of
T st
(
A is
open &
B is
open &
A in Bn . m &
B in Bn . n &
p in A &
Cl A c= B & not
q in B ) holds
pmet . [p,q] = 1 ) )
by A285;
A289:
for
rn being
Real st
rn in (dist (pmet,p)) .: A9 holds
rn >= 1
proof
let rn be
Real;
( rn in (dist (pmet,p)) .: A9 implies rn >= 1 )
assume
rn in (dist (pmet,p)) .: A9
;
rn >= 1
then consider a being
object such that A290:
a in dom (dist (pmet,p))
and A291:
a in A9
and A292:
rn = (dist (pmet,p)) . a
by FUNCT_1:def 6;
reconsider a =
a as
Point of
T by A290;
A293:
pmet . (
p,
a)
= (dist (pmet,p)) . a
by Def2;
U c= Cl U
by PRE_TOPC:18;
then
U c= A9 `
by A276;
then
U misses A9
by SUBSET_1:23;
then
not
a in U
by A291, XBOOLE_0:3;
hence
rn >= 1
by A279, A278, A281, A288, A292, A293;
verum
end;
take
PairFunc . [n,m]
;
for pmet being Function of [: the carrier of T, the carrier of T:],REAL st F9 . (PairFunc . [n,m]) = pmet holds
(lower_bound (pmet,A9)) . p > 0
the
carrier of
T = dom (dist (pmet,p))
by FUNCT_2:def 1;
then
lower_bound ((dist (pmet,p)) .: A9) >= 1
by A289, SEQ_4:43;
hence
for
pmet being
Function of
[: the carrier of T, the carrier of T:],
REAL st
F9 . (PairFunc . [n,m]) = pmet holds
(lower_bound (pmet,A9)) . p > 0
by A284, A287, Def3;
verum
end;
for
k being
Nat ex
pmet being
Function of
[: the carrier of T, the carrier of T:],
REAL st
(
F9 . k = pmet &
pmet is_a_pseudometric_of the
carrier of
T & ( for
pq being
Element of
[: the carrier of T, the carrier of T:] holds
pmet . pq <= 1 ) & ( for
pmet9 being
RealMap of
[:T,T:] st
pmet = pmet9 holds
pmet9 is
continuous ) )
proof
let k be
Nat;
ex pmet being Function of [: the carrier of T, the carrier of T:],REAL st
( F9 . k = pmet & pmet is_a_pseudometric_of the carrier of T & ( for pq being Element of [: the carrier of T, the carrier of T:] holds pmet . pq <= 1 ) & ( for pmet9 being RealMap of [:T,T:] st pmet = pmet9 holds
pmet9 is continuous ) )
A294:
k in NAT
by ORDINAL1:def 12;
then consider Fk being
RealMap of
[:T,T:] such that A295:
Fk = F . k
and A296:
for
n,
m being
Nat st
(PairFunc ") . k = [n,m] holds
S1[
n,
m,
Fk]
by A270;
NAT = rng PairFunc
by Th2, FUNCT_2:def 3;
then consider nm being
object such that A297:
nm in dom PairFunc
and A298:
k = PairFunc . nm
by FUNCT_1:def 3, A294;
consider n,
m being
object such that A299:
(
n in NAT &
m in NAT )
and A300:
nm = [n,m]
by A297, ZFMISC_1:def 2;
[n,m] = (PairFunc ") . k
by A297, A298, A300, Lm2, Th2, FUNCT_1:32;
then consider pmet being
Function of
[: the carrier of T, the carrier of T:],
REAL such that A301:
Fk = pmet
and A302:
Fk is
continuous
and A303:
pmet is_a_pseudometric_of the
carrier of
T
and A304:
for
p,
q being
Point of
T holds
(
pmet . [p,q] <= 1 & ( for
p,
q being
Point of
T st ex
A,
B being
Subset of
T st
(
A is
open &
B is
open &
A in Bn . m &
B in Bn . n &
p in A &
Cl A c= B & not
q in B ) holds
pmet . [p,q] = 1 ) )
by A299, A296;
take
pmet
;
( F9 . k = pmet & pmet is_a_pseudometric_of the carrier of T & ( for pq being Element of [: the carrier of T, the carrier of T:] holds pmet . pq <= 1 ) & ( for pmet9 being RealMap of [:T,T:] st pmet = pmet9 holds
pmet9 is continuous ) )
thus
(
F9 . k = pmet &
pmet is_a_pseudometric_of the
carrier of
T )
by A295, A301, A303;
( ( for pq being Element of [: the carrier of T, the carrier of T:] holds pmet . pq <= 1 ) & ( for pmet9 being RealMap of [:T,T:] st pmet = pmet9 holds
pmet9 is continuous ) )
thus
for
pq being
Element of
[: the carrier of T, the carrier of T:] holds
pmet . pq <= 1
for pmet9 being RealMap of [:T,T:] st pmet = pmet9 holds
pmet9 is continuous
thus
for
pmet9 being
RealMap of
[:T,T:] st
pmet = pmet9 holds
pmet9 is
continuous
by A301, A302;
verum
end;
hence
T is
metrizable
by A2, A272, Th17;
verum
end;
thus
( T is metrizable implies ( T is regular & T is T_1 & ex Bn being FamilySequence of T st Bn is Basis_sigma_locally_finite ) )
by NAGATA_1:15, NAGATA_1:16; verum