let n be Element of NAT ; :: thesis: 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 ) )
let e be real positive number ; :: thesis: 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); :: thesis: 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;
A1:
dom g = the carrier of I[01]
by FUNCT_2:def 1;
consider f being Function of (Closed-Interval-MSpace 0 ,1),(Euclid n) such that
A2:
f = g
by UNIFORM1:11;
A3:
f is uniformly_continuous
by A2, UNIFORM1:9;
A4:
e / 2 < e
by XREAL_1:218;
A5:
e / 2 > 0
by XREAL_1:217;
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 A3, UNIFORM1:def 1;
set s = min s1,(1 / 2);
A8:
0 <= min s1,(1 / 2)
by A6, XXREAL_0:20;
A9:
min s1,(1 / 2) <> 0
by A6, XXREAL_0:15;
then A10:
0 < min s1,(1 / 2)
by A6, XXREAL_0:20;
A11:
min s1,(1 / 2) <= s1
by XXREAL_0:17;
A12:
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);
:: thesis: ( dist u1,u2 < min s1,(1 / 2) implies dist (f /. u1),(f /. u2) < e / 2 )
assume
dist u1,
u2 < min s1,
(1 / 2)
;
:: thesis: dist (f /. u1),(f /. u2) < e / 2
then
dist u1,
u2 < s1
by A11, XXREAL_0:2;
hence
dist (f /. u1),
(f /. u2) < e / 2
by A7;
:: thesis: verum
end;
min s1,(1 / 2) <= 1 / 2
by XXREAL_0:17;
then A13:
2 / (min s1,(1 / 2)) >= 2 / (1 / 2)
by A8, A9, XREAL_1:120;
A14:
(min s1,(1 / 2)) / 2 > 0
by A8, A9, XREAL_1:217;
2 / (min s1,(1 / 2)) > 0
by A8, A9, XREAL_1:141;
then reconsider j = [/(2 / (min s1,(1 / 2)))\] as Element of NAT by INT_1:80;
A15:
2 / (min s1,(1 / 2)) <= [/(2 / (min s1,(1 / 2)))\]
by INT_1:def 5;
A16:
2 / (min s1,(1 / 2)) <= j
by INT_1:def 5;
0 < j
by A10, A15, XREAL_1:141;
then A17:
0 + 1 <= j
by NAT_1:13;
then A18:
1 in Seg j
by FINSEQ_1:3;
A19:
4 <= j
by A13, A16, XXREAL_0:2;
(2 / (min s1,(1 / 2))) - j <= 0
by A15, XREAL_1:49;
then
1 + ((2 / (min s1,(1 / 2))) - j) <= 1 + 0
by XREAL_1:8;
then A20:
((min s1,(1 / 2)) / 2) * (1 + ((2 / (min s1,(1 / 2))) - j)) <= ((min s1,(1 / 2)) / 2) * 1
by A14, XREAL_1:66;
defpred S1[ Nat, set ] means $2 = ((min s1,(1 / 2)) / 2) * ($1 - 1);
A22:
for k being Nat st k in Seg j holds
ex x being set st S1[k,x]
;
consider p being FinSequence such that
A23:
( dom p = Seg j & ( for k being Nat st k in Seg j holds
S1[k,p . k] ) )
from FINSEQ_1:sch 1(A22);
A24: p . 1 =
((min s1,(1 / 2)) / 2) * (1 - 1)
by A18, A23
.=
0
;
A25:
Seg (len p) = Seg j
by A23, FINSEQ_1:def 3;
A26:
len p = j
by A23, FINSEQ_1:def 3;
[/(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 A27:
((min s1,(1 / 2)) / 2) * (j - 1) < ((min s1,(1 / 2)) / 2) * (2 / (min s1,(1 / 2)))
by A14, XREAL_1:70;
A28:
((min s1,(1 / 2)) / 2) * (2 / (min s1,(1 / 2))) = (2 * (min s1,(1 / 2))) / (2 * (min s1,(1 / 2)))
by XCMPLX_1:77;
2 * (min s1,(1 / 2)) <> 0
by A6, XXREAL_0:15;
then A29:
(2 * (min s1,(1 / 2))) / (2 * (min s1,(1 / 2))) = 1
by XCMPLX_1:60;
then A30:
1 - (((min s1,(1 / 2)) / 2) * (j - 1)) = ((min s1,(1 / 2)) / 2) * (1 + ((2 / (min s1,(1 / 2))) - [/(2 / (min s1,(1 / 2)))\]))
by A28;
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 ;
:: thesis: 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;
:: thesis: ( 1 <= i & i < len p & r1 = p . i & r2 = p . (i + 1) implies ( r1 < r2 & r2 - r1 = (min s1,(1 / 2)) / 2 ) )
assume A32:
( 1
<= i &
i < len p &
r1 = p . i &
r2 = p . (i + 1) )
;
:: thesis: ( r1 < r2 & r2 - r1 = (min s1,(1 / 2)) / 2 )
then A33:
i in Seg j
by A25, FINSEQ_1:3;
A34:
i < i + 1
by NAT_1:13;
( 1
< i + 1 &
i + 1
<= len p )
by A32, NAT_1:13;
then A35:
i + 1
in Seg j
by A25, FINSEQ_1:3;
A36:
r1 = ((min s1,(1 / 2)) / 2) * (i - 1)
by A23, A32, A33;
A37:
r2 = ((min s1,(1 / 2)) / 2) * ((i + 1) - 1)
by A23, A32, A35;
i - 1
< (i + 1) - 1
by A34, XREAL_1:11;
hence
r1 < r2
by A14, A36, A37, XREAL_1:70;
:: thesis: r2 - r1 = (min s1,(1 / 2)) / 2
r2 - r1 = (((min s1,(1 / 2)) / 2) * i) - (((min s1,(1 / 2)) / 2) * (i - 1))
by A23, A32, A33, A37;
hence
r2 - r1 = (min s1,(1 / 2)) / 2
;
:: thesis: verum
end;
A38:
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 ;
:: thesis: for r1 being Real st 1 <= i & i <= len p & r1 = p . i holds
r1 < 1let r1 be
Real;
:: thesis: ( 1 <= i & i <= len p & r1 = p . i implies r1 < 1 )
assume A39:
( 1
<= i &
i <= len p &
r1 = p . i )
;
:: thesis: r1 < 1
then
i in Seg j
by A25, FINSEQ_1:3;
then A40:
r1 = ((min s1,(1 / 2)) / 2) * (i - 1)
by A23, A39;
i - 1
<= j - 1
by A26, A39, XREAL_1:11;
then
((min s1,(1 / 2)) / 2) * (i - 1) <= ((min s1,(1 / 2)) / 2) * (j - 1)
by A14, XREAL_1:66;
hence
r1 < 1
by A27, A28, A29, A40, XXREAL_0:2;
:: thesis: verum
end;
A41:
for r1 being Real st r1 = p . (len p) holds
1 - r1 <= (min s1,(1 / 2)) / 2
rng (p ^ <*1*>) c= REAL
then reconsider h1 = p ^ <*1*> as FinSequence of REAL by FINSEQ_1:def 4;
A50:
len h1 = (len p) + 1
by FINSEQ_2:19;
A51:
4 + 1 <= (len p) + 1
by A19, A26, XREAL_1:8;
A52:
h1 . 1 = 0
by A17, A24, A26, Lm2;
A53:
h1 . (len h1) = 1
by A50, FINSEQ_1:59;
A54:
rng p c= [.0 ,1.]
proof
let y be
set ;
:: according to TARSKI:def 3 :: thesis: ( not y in rng p or y in [.0 ,1.] )
assume
y in rng p
;
:: thesis: y in [.0 ,1.]
then consider x being
set such that A55:
(
x in dom p &
y = p . x )
by FUNCT_1:def 5;
A56:
x in Seg (len p)
by A55, FINSEQ_1:def 3;
reconsider nx =
x as
Element of
NAT by A55;
A57:
( 1
<= nx &
nx <= len p )
by A56, FINSEQ_1:3;
A58:
p . nx = ((min s1,(1 / 2)) / 2) * (nx - 1)
by A23, A55;
then reconsider ry =
p . nx as
Real ;
A59:
ry < 1
by A38, A57;
A60:
(min s1,(1 / 2)) / 2
>= 0
by A8;
nx - 1
>= 1
- 1
by A57, XREAL_1:11;
then
ry >= 0
by A58, A60;
then
y in { rs where rs is Real : ( 0 <= rs & rs <= 1 ) }
by A55, A59;
hence
y in [.0 ,1.]
by RCOMP_1:def 1;
:: thesis: verum
end;
A61:
rng <*1*> = {1}
by FINSEQ_1:55;
1 in { r where r is Real : ( 0 <= r & r <= 1 ) }
;
then A62:
1 in [.0 ,1.]
by RCOMP_1:def 1;
{1} c= [.0 ,1.]
then A63:
[.0 ,1.] \/ {1} = [.0 ,1.]
by XBOOLE_1:12;
rng h1 = (rng p) \/ {1}
by A61, FINSEQ_1:44;
then A64:
rng h1 c= [.0 ,1.] \/ {1}
by A54, XBOOLE_1:13;
Closed-Interval-TSpace 0 ,1 = TopSpaceMetr (Closed-Interval-MSpace 0 ,1)
by TOPMETR:def 8;
then A65: the carrier of I[01] =
the carrier of (Closed-Interval-MSpace 0 ,1)
by TOPMETR:16, TOPMETR:27
.=
[.0 ,1.]
by TOPMETR:14
;
A66:
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 ;
:: thesis: ( 1 <= i & i < len h1 implies h1 /. i < h1 /. (i + 1) )
assume A67:
( 1
<= i &
i < len h1 )
;
:: thesis: h1 /. i < h1 /. (i + 1)
then A68:
i <= len p
by A50, NAT_1:13;
A69:
i + 1
<= len h1
by A67, NAT_1:13;
A70:
1
< i + 1
by A67, NAT_1:13;
per cases
( i < len p or i >= len p )
;
suppose A71:
i < len p
;
:: thesis: h1 /. i < h1 /. (i + 1)A72:
h1 . i = h1 /. i
by A67, FINSEQ_4:24;
A73:
h1 . i = p . i
by A67, A71, FINSEQ_1:85;
A74:
i + 1
<= len p
by A71, NAT_1:13;
A75:
h1 . (i + 1) = h1 /. (i + 1)
by A69, A70, FINSEQ_4:24;
h1 . (i + 1) = p . (i + 1)
by A70, A74, FINSEQ_1:85;
hence
h1 /. i < h1 /. (i + 1)
by A31, A67, A71, A72, A73, A75;
:: thesis: verum end; suppose
i >= len p
;
:: thesis: h1 /. i < h1 /. (i + 1)then A76:
i = len p
by A68, XXREAL_0:1;
A77:
h1 /. (i + 1) =
h1 . (i + 1)
by A69, A70, FINSEQ_4:24
.=
1
by A76, FINSEQ_1:59
;
h1 /. i =
h1 . i
by A67, FINSEQ_4:24
.=
p . i
by A67, A68, FINSEQ_1:85
;
hence
h1 /. i < h1 /. (i + 1)
by A38, A67, A68, A77;
:: thesis: verum end; end;
end;
then A78:
h1 is increasing
by Lm3;
A79:
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 ;
:: thesis: ( 1 <= i & i < len h1 implies (h1 /. (i + 1)) - (h1 /. i) <= (min s1,(1 / 2)) / 2 )
assume A80:
( 1
<= i &
i < len h1 )
;
:: thesis: (h1 /. (i + 1)) - (h1 /. i) <= (min s1,(1 / 2)) / 2
then A81:
i <= len p
by A50, NAT_1:13;
A82:
i + 1
<= len h1
by A80, NAT_1:13;
A83:
1
< i + 1
by A80, NAT_1:13;
per cases
( i < len p or i >= len p )
;
suppose A84:
i < len p
;
:: thesis: (h1 /. (i + 1)) - (h1 /. i) <= (min s1,(1 / 2)) / 2A85:
h1 . i = h1 /. i
by A80, FINSEQ_4:24;
A86:
h1 . i = p . i
by A80, A84, FINSEQ_1:85;
A87:
i + 1
<= len p
by A84, NAT_1:13;
A88:
h1 . (i + 1) = h1 /. (i + 1)
by A82, A83, FINSEQ_4:24;
h1 . (i + 1) = p . (i + 1)
by A83, A87, FINSEQ_1:85;
hence
(h1 /. (i + 1)) - (h1 /. i) <= (min s1,(1 / 2)) / 2
by A31, A80, A84, A85, A86, A88;
:: thesis: verum end; suppose
i >= len p
;
:: thesis: (h1 /. (i + 1)) - (h1 /. i) <= (min s1,(1 / 2)) / 2then A89:
i = len p
by A81, XXREAL_0:1;
A90:
h1 /. (i + 1) =
h1 . (i + 1)
by A82, A83, FINSEQ_4:24
.=
1
by A89, FINSEQ_1:59
;
h1 /. i =
h1 . i
by A80, FINSEQ_4:24
.=
p . i
by A80, A81, FINSEQ_1:85
;
hence
(h1 /. (i + 1)) - (h1 /. i) <= (min s1,(1 / 2)) / 2
by A41, A89, A90;
:: thesis: verum end; end;
end;
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 ;
:: thesis: 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] ;
:: thesis: 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);
:: thesis: ( 1 <= i & i < len h1 & Q = [.(h1 /. i),(h1 /. (i + 1)).] & W = g .: Q implies diameter W < e )
assume A91:
( 1
<= i &
i < len h1 &
Q = [.(h1 /. i),(h1 /. (i + 1)).] &
W = g .: Q )
;
:: thesis: diameter W < e
then
h1 /. i < h1 /. (i + 1)
by A66;
then A92:
Q <> {}
by A91, XXREAL_1:1;
consider x1 being
Element of
Q;
x1 in Q
by A92;
then A93:
g . x1 in W
by A1, A91, FUNCT_1:def 12;
A94:
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);
:: thesis: ( x in W & y in W implies dist x,y <= e / 2 )
assume A95:
(
x in W &
y in W )
;
:: thesis: dist x,y <= e / 2
then consider x3 being
set such that A96:
(
x3 in dom g &
x3 in Q &
x = g . x3 )
by A91, FUNCT_1:def 12;
reconsider x3 =
x3 as
Element of
(Closed-Interval-MSpace 0 ,1) by A96, Lm1, TOPMETR:16;
consider y3 being
set such that A97:
(
y3 in dom g &
y3 in Q &
y = g . y3 )
by A91, A95, FUNCT_1:def 12;
reconsider y3 =
y3 as
Element of
(Closed-Interval-MSpace 0 ,1) by A97, Lm1, TOPMETR:16;
A98:
f . x3 = f /. x3
;
A99:
f . y3 = f /. y3
;
reconsider r3 =
x3 as
Real by A91, A96;
reconsider s3 =
y3 as
Real by A91, A97;
A100:
abs (r3 - s3) <= (h1 /. (i + 1)) - (h1 /. i)
by A91, A96, A97, UNIFORM1:14;
(h1 /. (i + 1)) - (h1 /. i) <= (min s1,(1 / 2)) / 2
by A79, A91;
then
abs (r3 - s3) <= (min s1,(1 / 2)) / 2
by A100, XXREAL_0:2;
then A101:
dist x3,
y3 <= (min s1,(1 / 2)) / 2
by HEINE:1;
(min s1,(1 / 2)) / 2
< min s1,
(1 / 2)
by A8, A9, XREAL_1:218;
then
dist x3,
y3 < min s1,
(1 / 2)
by A101, XXREAL_0:2;
hence
dist x,
y <= e / 2
by A2, A12, A96, A97, A98, A99;
:: thesis: verum
end;
then
W is
bounded
by A5, TBSP_1:def 9;
then
diameter W <= e / 2
by A93, A94, TBSP_1:def 10;
hence
diameter W < e
by A4, XXREAL_0:2;
:: thesis: verum
end;
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 A50, A51, A52, A53, A63, A64, A65, A78; :: thesis: verum