let n be Nat; for e being positive Real
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 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.]
by A1, TARSKI:def 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 7;
then A3: the carrier of I[01] =
the carrier of (Closed-Interval-MSpace (0,1))
by TOPMETR:12, TOPMETR:20
.=
[.0,1.]
by TOPMETR:10
;
let e be positive Real; 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 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 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 ;
A4:
n in NAT
by ORDINAL1:def 12;
then reconsider f = g as Function of (Closed-Interval-MSpace (0,1)),(Euclid n) by UNIFORM1:10;
A5:
e / 2 < e
by XREAL_1:216;
A6:
e / 2 > 0
by XREAL_1:215;
f is uniformly_continuous
by UNIFORM1:8, A4;
then consider s1 being Real such that
A7:
0 < s1
and
A8:
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 A6, UNIFORM1:def 1;
set s = min (s1,(1 / 2));
defpred S1[ Nat, object ] means $2 = ((min (s1,(1 / 2))) / 2) * ($1 - 1);
A9:
0 <= min (s1,(1 / 2))
by A7, XXREAL_0:20;
then reconsider j = [/(2 / (min (s1,(1 / 2))))\] as Nat by INT_1:53;
A10:
2 / (min (s1,(1 / 2))) <= j
by INT_1:def 7;
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));
( 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 A11, XXREAL_0:2;
hence
dist (
(f /. u1),
(f /. u2))
< e / 2
by A8;
verum
end;
A13:
2 / (min (s1,(1 / 2))) <= [/(2 / (min (s1,(1 / 2))))\]
by INT_1:def 7;
then
(2 / (min (s1,(1 / 2)))) - j <= 0
by XREAL_1:47;
then
1 + ((2 / (min (s1,(1 / 2)))) - j) <= 1 + 0
by XREAL_1:6;
then A14:
((min (s1,(1 / 2))) / 2) * (1 + ((2 / (min (s1,(1 / 2)))) - j)) <= ((min (s1,(1 / 2))) / 2) * 1
by A9, XREAL_1:64;
A15:
for k being Nat st k in Seg j holds
ex x being object st S1[k,x]
;
consider p being FinSequence such that
A16:
( dom p = Seg j & ( for k being Nat st k in Seg j holds
S1[k,p . k] ) )
from FINSEQ_1:sch 1(A15);
A17:
Seg (len p) = Seg j
by A16, FINSEQ_1:def 3;
rng (p ^ <*1*>) c= REAL
then reconsider h1 = p ^ <*1*> as FinSequence of REAL by FINSEQ_1:def 4;
A28:
len h1 = (len p) + 1
by FINSEQ_2:16;
j in NAT
by ORDINAL1:def 12;
then A29:
len p = j
by A16, FINSEQ_1:def 3;
A30:
min (s1,(1 / 2)) <> 0
by A7, XXREAL_0:15;
then
2 / (min (s1,(1 / 2))) >= 2 / (1 / 2)
by A9, XREAL_1:118, XXREAL_0:17;
then
4 <= j
by A10, XXREAL_0:2;
then A31:
4 + 1 <= (len p) + 1
by A29, XREAL_1:6;
A32:
(min (s1,(1 / 2))) / 2 > 0
by A9, A30, XREAL_1:215;
A33:
for i being 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
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 A34:
( 1
<= i &
i < len p )
and A35:
r1 = p . i
and A36:
r2 = p . (i + 1)
;
( r1 < r2 & r2 - r1 = (min (s1,(1 / 2))) / 2 )
( 1
< i + 1 &
i + 1
<= len p )
by A34, NAT_1:13;
then
i + 1
in Seg j
by A17, FINSEQ_1:1;
then A37:
r2 = ((min (s1,(1 / 2))) / 2) * ((i + 1) - 1)
by A16, A36;
i < i + 1
by NAT_1:13;
then A38:
i - 1
< (i + 1) - 1
by XREAL_1:9;
A39:
i in Seg j
by A17, A34, FINSEQ_1:1;
then
r1 = ((min (s1,(1 / 2))) / 2) * (i - 1)
by A16, A35;
hence
r1 < r2
by A32, A37, A38, XREAL_1:68;
r2 - r1 = (min (s1,(1 / 2))) / 2
r2 - r1 = (((min (s1,(1 / 2))) / 2) * i) - (((min (s1,(1 / 2))) / 2) * (i - 1))
by A16, A35, A39, A37;
hence
r2 - r1 = (min (s1,(1 / 2))) / 2
;
verum
end;
0 < min (s1,(1 / 2))
by A7, A30, XXREAL_0:20;
then
0 < j
by A13, XREAL_1:139;
then A40:
0 + 1 <= j
by NAT_1:13;
then
1 in Seg j
by FINSEQ_1:1;
then p . 1 =
((min (s1,(1 / 2))) / 2) * (1 - 1)
by A16
.=
0
;
then A41:
h1 . 1 = 0
by A40, A29, Lm2;
2 * (min (s1,(1 / 2))) <> 0
by A7, XXREAL_0:15;
then A42:
( ((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_1:76;
then A43:
1 - (((min (s1,(1 / 2))) / 2) * (j - 1)) = ((min (s1,(1 / 2))) / 2) * (1 + ((2 / (min (s1,(1 / 2)))) - [/(2 / (min (s1,(1 / 2))))\]))
;
A44:
for r1 being Real st r1 = p . (len p) holds
1 - r1 <= (min (s1,(1 / 2))) / 2
by A40, A29, FINSEQ_1:1, A14, A16, A43;
A45:
for i being Nat st 1 <= i & i < len h1 holds
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
proof
let i be
Nat;
( 1 <= i & i < len h1 implies (h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2 )
assume that A46:
1
<= i
and A47:
i < len h1
;
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
A48:
i + 1
<= len h1
by A47, NAT_1:13;
A49:
i <= len p
by A28, A47, NAT_1:13;
A50:
1
< i + 1
by A46, NAT_1:13;
per cases
( i < len p or i >= len p )
;
suppose A51:
i < len p
;
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2then
i + 1
<= len p
by NAT_1:13;
then A52:
h1 . (i + 1) = p . (i + 1)
by A50, FINSEQ_1:64;
A53:
h1 . i = p . i
by A46, A51, FINSEQ_1:64;
(
h1 . i = h1 /. i &
h1 . (i + 1) = h1 /. (i + 1) )
by A46, A47, A48, A50, FINSEQ_4:15;
hence
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
by A33, A46, A51, A53, A52;
verum end; suppose
i >= len p
;
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2then A54:
i = len p
by A49, XXREAL_0:1;
A55:
h1 /. i =
h1 . i
by A46, A47, FINSEQ_4:15
.=
p . i
by A46, A49, FINSEQ_1:64
;
h1 /. (i + 1) =
h1 . (i + 1)
by A48, A50, FINSEQ_4:15
.=
1
by A54, FINSEQ_1:42
;
hence
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
by A44, A54, A55;
verum end; end;
end;
[/(2 / (min (s1,(1 / 2))))\] < (2 / (min (s1,(1 / 2)))) + 1
by INT_1:def 7;
then
[/(2 / (min (s1,(1 / 2))))\] - 1 < ((2 / (min (s1,(1 / 2)))) + 1) - 1
by XREAL_1:9;
then A56:
((min (s1,(1 / 2))) / 2) * (j - 1) < ((min (s1,(1 / 2))) / 2) * (2 / (min (s1,(1 / 2))))
by A32, XREAL_1:68;
A57:
for i being Nat
for r1 being Real st 1 <= i & i <= len p & r1 = p . i holds
r1 < 1
proof
let i be
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 A58:
1
<= i
and A59:
i <= len p
and A60:
r1 = p . i
;
r1 < 1
i - 1
<= j - 1
by A29, A59, XREAL_1:9;
then A61:
((min (s1,(1 / 2))) / 2) * (i - 1) <= ((min (s1,(1 / 2))) / 2) * (j - 1)
by A9, XREAL_1:64;
i in Seg j
by A17, A58, A59, FINSEQ_1:1;
then
r1 = ((min (s1,(1 / 2))) / 2) * (i - 1)
by A16, A60;
hence
r1 < 1
by A56, A42, A61, XXREAL_0:2;
verum
end;
A62:
for i being Nat st 1 <= i & i < len h1 holds
h1 /. i < h1 /. (i + 1)
proof
let i be
Nat;
( 1 <= i & i < len h1 implies h1 /. i < h1 /. (i + 1) )
assume that A63:
1
<= i
and A64:
i < len h1
;
h1 /. i < h1 /. (i + 1)
A65:
i + 1
<= len h1
by A64, NAT_1:13;
A66:
1
< i + 1
by A63, NAT_1:13;
A67:
i <= len p
by A28, A64, NAT_1:13;
per cases
( i < len p or i >= len p )
;
suppose A68:
i < len p
;
h1 /. i < h1 /. (i + 1)then
i + 1
<= len p
by NAT_1:13;
then A69:
h1 . (i + 1) = p . (i + 1)
by A66, FINSEQ_1:64;
A70:
h1 . i = p . i
by A63, A68, FINSEQ_1:64;
(
h1 . i = h1 /. i &
h1 . (i + 1) = h1 /. (i + 1) )
by A63, A64, A65, A66, FINSEQ_4:15;
hence
h1 /. i < h1 /. (i + 1)
by A33, A63, A68, A70, A69;
verum end; suppose
i >= len p
;
h1 /. i < h1 /. (i + 1)then A71:
i = len p
by A67, XXREAL_0:1;
A72:
h1 /. (i + 1) =
h1 . (i + 1)
by A65, A66, FINSEQ_4:15
.=
1
by A71, FINSEQ_1:42
;
h1 /. i =
h1 . i
by A63, A64, FINSEQ_4:15
.=
p . i
by A63, A67, FINSEQ_1:64
;
hence
h1 /. i < h1 /. (i + 1)
by A57, A63, A67, A72;
verum end; end;
end;
A73:
dom g = the carrier of I[01]
by FUNCT_2:def 1;
A74:
for i being 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
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 A75:
( 1
<= i &
i < len h1 )
and A76:
Q = [.(h1 /. i),(h1 /. (i + 1)).]
and A77:
W = g .: Q
;
diameter W < e
h1 /. i < h1 /. (i + 1)
by A62, A75;
then A78:
Q <> {}
by A76, XXREAL_1:1;
A79:
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 A80:
x in W
and A81:
y in W
;
dist (x,y) <= e / 2
consider x3 being
object such that A82:
x3 in dom g
and A83:
x3 in Q
and A84:
x = g . x3
by A77, A80, FUNCT_1:def 6;
reconsider x3 =
x3 as
Element of
(Closed-Interval-MSpace (0,1)) by A82, Lm1, TOPMETR:12;
reconsider r3 =
x3 as
Real by A83;
A85:
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
by A45, A75;
consider y3 being
object such that A86:
y3 in dom g
and A87:
y3 in Q
and A88:
y = g . y3
by A77, A81, FUNCT_1:def 6;
reconsider y3 =
y3 as
Element of
(Closed-Interval-MSpace (0,1)) by A86, Lm1, TOPMETR:12;
reconsider s3 =
y3 as
Real by A87;
A89:
(
f . x3 = f /. x3 &
f . y3 = f /. y3 )
;
|.(r3 - s3).| <= (h1 /. (i + 1)) - (h1 /. i)
by A76, A83, A87, UNIFORM1:12;
then
|.(r3 - s3).| <= (min (s1,(1 / 2))) / 2
by A85, XXREAL_0:2;
then A90:
dist (
x3,
y3)
<= (min (s1,(1 / 2))) / 2
by HEINE:1;
(min (s1,(1 / 2))) / 2
< min (
s1,
(1 / 2))
by A9, A30, XREAL_1:216;
then
dist (
x3,
y3)
< min (
s1,
(1 / 2))
by A90, XXREAL_0:2;
hence
dist (
x,
y)
<= e / 2
by A12, A84, A88, A89;
verum
end;
then
W is
bounded
by A6, TBSP_1:def 7;
then
diameter W <= e / 2
by A73, A77, A78, A79, TBSP_1:def 8;
hence
diameter W < e
by A5, XXREAL_0:2;
verum
end;
A91:
rng p c= [.0,1.]
proof
let y be
object ;
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
object such that A92:
x in dom p
and A93:
y = p . x
by FUNCT_1:def 3;
reconsider nx =
x as
Nat by A92;
A94:
p . nx = ((min (s1,(1 / 2))) / 2) * (nx - 1)
by A16, A92;
then reconsider ry =
p . nx as
Real ;
A95:
x in Seg (len p)
by A92, FINSEQ_1:def 3;
then A96:
1
<= nx
by FINSEQ_1:1;
then A97:
nx - 1
>= 1
- 1
by XREAL_1:9;
nx <= len p
by A95, FINSEQ_1:1;
then
ry < 1
by A57, A96;
then
y in { rs where rs is Real : ( 0 <= rs & rs <= 1 ) }
by A9, A93, A94, A97;
hence
y in [.0,1.]
by RCOMP_1:def 1;
verum
end;
rng <*1*> = {1}
by FINSEQ_1:38;
then
rng h1 = (rng p) \/ {1}
by FINSEQ_1:31;
then A98:
rng h1 c= [.0,1.] \/ {1}
by A91, XBOOLE_1:13;
h1 . (len h1) = 1
by A28, FINSEQ_1:42;
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 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 A28, A31, A41, A2, A98, A3, A62, A74, Lm3; verum