let n be Element of NAT ; for e being real positive number
for g being continuous Function of I[01],(TOP-REAL n) ex h being FinSequence of REAL st
( h . 1 = 0 & h . (len h) = 1 & 5 <= len h & rng h c= the carrier of I[01] & h is increasing & ( for i being Element of NAT
for Q being Subset of I[01]
for W being Subset of (Euclid n) st 1 <= i & i < len h & Q = [.(h /. i),(h /. (i + 1)).] & W = g .: Q holds
diameter W < e ) )
1 in { r where r is Real : ( 0 <= r & r <= 1 ) }
;
then A1:
1 in [.0,1.]
by RCOMP_1:def 1;
{1} c= [.0,1.]
then A2:
[.0,1.] \/ {1} = [.0,1.]
by XBOOLE_1:12;
Closed-Interval-TSpace (0,1) = TopSpaceMetr (Closed-Interval-MSpace (0,1))
by TOPMETR:def 8;
then A3: the carrier of I[01] =
the carrier of (Closed-Interval-MSpace (0,1))
by TOPMETR:16, TOPMETR:27
.=
[.0,1.]
by TOPMETR:14
;
let e be real positive number ; for g being continuous Function of I[01],(TOP-REAL n) ex h being FinSequence of REAL st
( h . 1 = 0 & h . (len h) = 1 & 5 <= len h & rng h c= the carrier of I[01] & h is increasing & ( for i being Element of NAT
for Q being Subset of I[01]
for W being Subset of (Euclid n) st 1 <= i & i < len h & Q = [.(h /. i),(h /. (i + 1)).] & W = g .: Q holds
diameter W < e ) )
let g be continuous Function of I[01],(TOP-REAL n); ex h being FinSequence of REAL st
( h . 1 = 0 & h . (len h) = 1 & 5 <= len h & rng h c= the carrier of I[01] & h is increasing & ( for i being Element of NAT
for Q being Subset of I[01]
for W being Subset of (Euclid n) st 1 <= i & i < len h & Q = [.(h /. i),(h /. (i + 1)).] & W = g .: Q holds
diameter W < e ) )
reconsider e = e as positive Real by XREAL_0:def 1;
reconsider f = g as Function of (Closed-Interval-MSpace (0,1)),(Euclid n) by UNIFORM1:11;
A4:
e / 2 < e
by XREAL_1:218;
A5:
e / 2 > 0
by XREAL_1:217;
f is uniformly_continuous
by UNIFORM1:9;
then consider s1 being Real such that
A6:
0 < s1
and
A7:
for u1, u2 being Element of (Closed-Interval-MSpace (0,1)) st dist (u1,u2) < s1 holds
dist ((f /. u1),(f /. u2)) < e / 2
by A5, UNIFORM1:def 1;
set s = min (s1,(1 / 2));
defpred S1[ Nat, set ] means $2 = ((min (s1,(1 / 2))) / 2) * ($1 - 1);
A8:
0 <= min (s1,(1 / 2))
by A6, XXREAL_0:20;
then reconsider j = [/(2 / (min (s1,(1 / 2))))\] as Element of NAT by INT_1:80;
A9:
2 / (min (s1,(1 / 2))) <= j
by INT_1:def 5;
A10:
min (s1,(1 / 2)) <= s1
by XXREAL_0:17;
A11:
for u1, u2 being Element of (Closed-Interval-MSpace (0,1)) st dist (u1,u2) < min (s1,(1 / 2)) holds
dist ((f /. u1),(f /. u2)) < e / 2
proof
let u1,
u2 be
Element of
(Closed-Interval-MSpace (0,1));
( dist (u1,u2) < min (s1,(1 / 2)) implies dist ((f /. u1),(f /. u2)) < e / 2 )
assume
dist (
u1,
u2)
< min (
s1,
(1 / 2))
;
dist ((f /. u1),(f /. u2)) < e / 2
then
dist (
u1,
u2)
< s1
by A10, XXREAL_0:2;
hence
dist (
(f /. u1),
(f /. u2))
< e / 2
by A7;
verum
end;
A12:
2 / (min (s1,(1 / 2))) <= [/(2 / (min (s1,(1 / 2))))\]
by INT_1:def 5;
then
(2 / (min (s1,(1 / 2)))) - j <= 0
by XREAL_1:49;
then
1 + ((2 / (min (s1,(1 / 2)))) - j) <= 1 + 0
by XREAL_1:8;
then A13:
((min (s1,(1 / 2))) / 2) * (1 + ((2 / (min (s1,(1 / 2)))) - j)) <= ((min (s1,(1 / 2))) / 2) * 1
by A8, XREAL_1:66;
A14:
for k being Nat st k in Seg j holds
ex x being set st S1[k,x]
;
consider p being FinSequence such that
A15:
( dom p = Seg j & ( for k being Nat st k in Seg j holds
S1[k,p . k] ) )
from FINSEQ_1:sch 1(A14);
A16:
Seg (len p) = Seg j
by A15, FINSEQ_1:def 3;
rng (p ^ <*1*>) c= REAL
then reconsider h1 = p ^ <*1*> as FinSequence of REAL by FINSEQ_1:def 4;
A26:
len h1 = (len p) + 1
by FINSEQ_2:19;
A27:
len p = j
by A15, FINSEQ_1:def 3;
A28:
min (s1,(1 / 2)) <> 0
by A6, XXREAL_0:15;
then
2 / (min (s1,(1 / 2))) >= 2 / (1 / 2)
by A8, XREAL_1:120, XXREAL_0:17;
then
4 <= j
by A9, XXREAL_0:2;
then A29:
4 + 1 <= (len p) + 1
by A27, XREAL_1:8;
A30:
(min (s1,(1 / 2))) / 2 > 0
by A8, A28, XREAL_1:217;
A31:
for i being Element of NAT
for r1, r2 being Real st 1 <= i & i < len p & r1 = p . i & r2 = p . (i + 1) holds
( r1 < r2 & r2 - r1 = (min (s1,(1 / 2))) / 2 )
proof
let i be
Element of
NAT ;
for r1, r2 being Real st 1 <= i & i < len p & r1 = p . i & r2 = p . (i + 1) holds
( r1 < r2 & r2 - r1 = (min (s1,(1 / 2))) / 2 )let r1,
r2 be
Real;
( 1 <= i & i < len p & r1 = p . i & r2 = p . (i + 1) implies ( r1 < r2 & r2 - r1 = (min (s1,(1 / 2))) / 2 ) )
assume that A32:
( 1
<= i &
i < len p )
and A33:
r1 = p . i
and A34:
r2 = p . (i + 1)
;
( r1 < r2 & r2 - r1 = (min (s1,(1 / 2))) / 2 )
( 1
< i + 1 &
i + 1
<= len p )
by A32, NAT_1:13;
then
i + 1
in Seg j
by A16, FINSEQ_1:3;
then A35:
r2 = ((min (s1,(1 / 2))) / 2) * ((i + 1) - 1)
by A15, A34;
i < i + 1
by NAT_1:13;
then A36:
i - 1
< (i + 1) - 1
by XREAL_1:11;
A37:
i in Seg j
by A16, A32, FINSEQ_1:3;
then
r1 = ((min (s1,(1 / 2))) / 2) * (i - 1)
by A15, A33;
hence
r1 < r2
by A30, A35, A36, XREAL_1:70;
r2 - r1 = (min (s1,(1 / 2))) / 2
r2 - r1 = (((min (s1,(1 / 2))) / 2) * i) - (((min (s1,(1 / 2))) / 2) * (i - 1))
by A15, A33, A37, A35;
hence
r2 - r1 = (min (s1,(1 / 2))) / 2
;
verum
end;
0 < min (s1,(1 / 2))
by A6, A28, XXREAL_0:20;
then
0 < j
by A12, XREAL_1:141;
then A38:
0 + 1 <= j
by NAT_1:13;
then
1 in Seg j
by FINSEQ_1:3;
then p . 1 =
((min (s1,(1 / 2))) / 2) * (1 - 1)
by A15
.=
0
;
then A39:
h1 . 1 = 0
by A38, A27, Lm2;
2 * (min (s1,(1 / 2))) <> 0
by A6, XXREAL_0:15;
then A40:
( ((min (s1,(1 / 2))) / 2) * (2 / (min (s1,(1 / 2)))) = (2 * (min (s1,(1 / 2)))) / (2 * (min (s1,(1 / 2)))) & (2 * (min (s1,(1 / 2)))) / (2 * (min (s1,(1 / 2)))) = 1 )
by XCMPLX_1:60, XCMPLX_1:77;
then A41:
1 - (((min (s1,(1 / 2))) / 2) * (j - 1)) = ((min (s1,(1 / 2))) / 2) * (1 + ((2 / (min (s1,(1 / 2)))) - [/(2 / (min (s1,(1 / 2))))\]))
;
A42:
for r1 being Real st r1 = p . (len p) holds
1 - r1 <= (min (s1,(1 / 2))) / 2
A44:
for i being Element of NAT st 1 <= i & i < len h1 holds
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
proof
let i be
Element of
NAT ;
( 1 <= i & i < len h1 implies (h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2 )
assume that A45:
1
<= i
and A46:
i < len h1
;
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
A47:
i + 1
<= len h1
by A46, NAT_1:13;
A48:
i <= len p
by A26, A46, NAT_1:13;
A49:
1
< i + 1
by A45, NAT_1:13;
per cases
( i < len p or i >= len p )
;
suppose A50:
i < len p
;
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2then
i + 1
<= len p
by NAT_1:13;
then A51:
h1 . (i + 1) = p . (i + 1)
by A49, FINSEQ_1:85;
A52:
h1 . i = p . i
by A45, A50, FINSEQ_1:85;
(
h1 . i = h1 /. i &
h1 . (i + 1) = h1 /. (i + 1) )
by A45, A46, A47, A49, FINSEQ_4:24;
hence
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
by A31, A45, A50, A52, A51;
verum end; suppose
i >= len p
;
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2then A53:
i = len p
by A48, XXREAL_0:1;
A54:
h1 /. i =
h1 . i
by A45, A46, FINSEQ_4:24
.=
p . i
by A45, A48, FINSEQ_1:85
;
h1 /. (i + 1) =
h1 . (i + 1)
by A47, A49, FINSEQ_4:24
.=
1
by A53, FINSEQ_1:59
;
hence
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
by A42, A53, A54;
verum end; end;
end;
[/(2 / (min (s1,(1 / 2))))\] < (2 / (min (s1,(1 / 2)))) + 1
by INT_1:def 5;
then
[/(2 / (min (s1,(1 / 2))))\] - 1 < ((2 / (min (s1,(1 / 2)))) + 1) - 1
by XREAL_1:11;
then A55:
((min (s1,(1 / 2))) / 2) * (j - 1) < ((min (s1,(1 / 2))) / 2) * (2 / (min (s1,(1 / 2))))
by A30, XREAL_1:70;
A56:
for i being Element of NAT
for r1 being Real st 1 <= i & i <= len p & r1 = p . i holds
r1 < 1
proof
let i be
Element of
NAT ;
for r1 being Real st 1 <= i & i <= len p & r1 = p . i holds
r1 < 1let r1 be
Real;
( 1 <= i & i <= len p & r1 = p . i implies r1 < 1 )
assume that A57:
1
<= i
and A58:
i <= len p
and A59:
r1 = p . i
;
r1 < 1
i - 1
<= j - 1
by A27, A58, XREAL_1:11;
then A60:
((min (s1,(1 / 2))) / 2) * (i - 1) <= ((min (s1,(1 / 2))) / 2) * (j - 1)
by A8, XREAL_1:66;
i in Seg j
by A16, A57, A58, FINSEQ_1:3;
then
r1 = ((min (s1,(1 / 2))) / 2) * (i - 1)
by A15, A59;
hence
r1 < 1
by A55, A40, A60, XXREAL_0:2;
verum
end;
A61:
for i being Element of NAT st 1 <= i & i < len h1 holds
h1 /. i < h1 /. (i + 1)
proof
let i be
Element of
NAT ;
( 1 <= i & i < len h1 implies h1 /. i < h1 /. (i + 1) )
assume that A62:
1
<= i
and A63:
i < len h1
;
h1 /. i < h1 /. (i + 1)
A64:
i + 1
<= len h1
by A63, NAT_1:13;
A65:
1
< i + 1
by A62, NAT_1:13;
A66:
i <= len p
by A26, A63, NAT_1:13;
per cases
( i < len p or i >= len p )
;
suppose A67:
i < len p
;
h1 /. i < h1 /. (i + 1)then
i + 1
<= len p
by NAT_1:13;
then A68:
h1 . (i + 1) = p . (i + 1)
by A65, FINSEQ_1:85;
A69:
h1 . i = p . i
by A62, A67, FINSEQ_1:85;
(
h1 . i = h1 /. i &
h1 . (i + 1) = h1 /. (i + 1) )
by A62, A63, A64, A65, FINSEQ_4:24;
hence
h1 /. i < h1 /. (i + 1)
by A31, A62, A67, A69, A68;
verum end; suppose
i >= len p
;
h1 /. i < h1 /. (i + 1)then A70:
i = len p
by A66, XXREAL_0:1;
A71:
h1 /. (i + 1) =
h1 . (i + 1)
by A64, A65, FINSEQ_4:24
.=
1
by A70, FINSEQ_1:59
;
h1 /. i =
h1 . i
by A62, A63, FINSEQ_4:24
.=
p . i
by A62, A66, FINSEQ_1:85
;
hence
h1 /. i < h1 /. (i + 1)
by A56, A62, A66, A71;
verum end; end;
end;
A72:
dom g = the carrier of I[01]
by FUNCT_2:def 1;
A73:
for i being Element of NAT
for Q being Subset of I[01]
for W being Subset of (Euclid n) st 1 <= i & i < len h1 & Q = [.(h1 /. i),(h1 /. (i + 1)).] & W = g .: Q holds
diameter W < e
proof
let i be
Element of
NAT ;
for Q being Subset of I[01]
for W being Subset of (Euclid n) st 1 <= i & i < len h1 & Q = [.(h1 /. i),(h1 /. (i + 1)).] & W = g .: Q holds
diameter W < elet Q be
Subset of
I[01];
for W being Subset of (Euclid n) st 1 <= i & i < len h1 & Q = [.(h1 /. i),(h1 /. (i + 1)).] & W = g .: Q holds
diameter W < elet W be
Subset of
(Euclid n);
( 1 <= i & i < len h1 & Q = [.(h1 /. i),(h1 /. (i + 1)).] & W = g .: Q implies diameter W < e )
assume that A74:
( 1
<= i &
i < len h1 )
and A75:
Q = [.(h1 /. i),(h1 /. (i + 1)).]
and A76:
W = g .: Q
;
diameter W < e
h1 /. i < h1 /. (i + 1)
by A61, A74;
then A77:
Q <> {}
by A75, XXREAL_1:1;
A78:
for
x,
y being
Point of
(Euclid n) st
x in W &
y in W holds
dist (
x,
y)
<= e / 2
proof
let x,
y be
Point of
(Euclid n);
( x in W & y in W implies dist (x,y) <= e / 2 )
assume that A79:
x in W
and A80:
y in W
;
dist (x,y) <= e / 2
consider x3 being
set such that A81:
x3 in dom g
and A82:
x3 in Q
and A83:
x = g . x3
by A76, A79, FUNCT_1:def 12;
reconsider x3 =
x3 as
Element of
(Closed-Interval-MSpace (0,1)) by A81, Lm1, TOPMETR:16;
reconsider r3 =
x3 as
Real by A75, A82;
A84:
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
by A44, A74;
consider y3 being
set such that A85:
y3 in dom g
and A86:
y3 in Q
and A87:
y = g . y3
by A76, A80, FUNCT_1:def 12;
reconsider y3 =
y3 as
Element of
(Closed-Interval-MSpace (0,1)) by A85, Lm1, TOPMETR:16;
reconsider s3 =
y3 as
Real by A75, A86;
A88:
(
f . x3 = f /. x3 &
f . y3 = f /. y3 )
;
abs (r3 - s3) <= (h1 /. (i + 1)) - (h1 /. i)
by A75, A82, A86, UNIFORM1:14;
then
abs (r3 - s3) <= (min (s1,(1 / 2))) / 2
by A84, XXREAL_0:2;
then A89:
dist (
x3,
y3)
<= (min (s1,(1 / 2))) / 2
by HEINE:1;
(min (s1,(1 / 2))) / 2
< min (
s1,
(1 / 2))
by A8, A28, XREAL_1:218;
then
dist (
x3,
y3)
< min (
s1,
(1 / 2))
by A89, XXREAL_0:2;
hence
dist (
x,
y)
<= e / 2
by A11, A83, A87, A88;
verum
end;
then
W is
bounded
by A5, TBSP_1:def 9;
then
diameter W <= e / 2
by A72, A76, A77, A78, TBSP_1:def 10;
hence
diameter W < e
by A4, XXREAL_0:2;
verum
consider x1 being
Element of
Q;
end;
A90:
rng p c= [.0,1.]
proof
let y be
set ;
TARSKI:def 3 ( not y in rng p or y in [.0,1.] )
assume
y in rng p
;
y in [.0,1.]
then consider x being
set such that A91:
x in dom p
and A92:
y = p . x
by FUNCT_1:def 5;
reconsider nx =
x as
Element of
NAT by A91;
A93:
p . nx = ((min (s1,(1 / 2))) / 2) * (nx - 1)
by A15, A91;
then reconsider ry =
p . nx as
Real ;
A94:
x in Seg (len p)
by A91, FINSEQ_1:def 3;
then A95:
1
<= nx
by FINSEQ_1:3;
then A96:
nx - 1
>= 1
- 1
by XREAL_1:11;
nx <= len p
by A94, FINSEQ_1:3;
then
ry < 1
by A56, A95;
then
y in { rs where rs is Real : ( 0 <= rs & rs <= 1 ) }
by A8, A92, A93, A96;
hence
y in [.0,1.]
by RCOMP_1:def 1;
verum
end;
rng <*1*> = {1}
by FINSEQ_1:55;
then
rng h1 = (rng p) \/ {1}
by FINSEQ_1:44;
then A97:
rng h1 c= [.0,1.] \/ {1}
by A90, XBOOLE_1:13;
h1 . (len h1) = 1
by A26, FINSEQ_1:59;
hence
ex h being FinSequence of REAL st
( h . 1 = 0 & h . (len h) = 1 & 5 <= len h & rng h c= the carrier of I[01] & h is increasing & ( for i being Element of NAT
for Q being Subset of I[01]
for W being Subset of (Euclid n) st 1 <= i & i < len h & Q = [.(h /. i),(h /. (i + 1)).] & W = g .: Q holds
diameter W < e ) )
by A26, A29, A39, A2, A97, A3, A61, A73, Lm3; verum