let n be Element of NAT ; for e being Real
for g being Function of I[01],(TOP-REAL n)
for p1, p2 being Element of (TOP-REAL n) st e > 0 & g is continuous holds
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 Real; for g being Function of I[01],(TOP-REAL n)
for p1, p2 being Element of (TOP-REAL n) st e > 0 & g is continuous holds
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 Function of I[01],(TOP-REAL n); for p1, p2 being Element of (TOP-REAL n) st e > 0 & g is continuous holds
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 p1, p2 be Element of (TOP-REAL n); ( e > 0 & g is continuous implies 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 ) ) )
assume that
A4:
e > 0
and
A5:
g is continuous
; 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 ) )
A6:
e / 2 > 0
by A4, XREAL_1:215;
A7:
TopStruct(# the carrier of (TOP-REAL n), the topology of (TOP-REAL n) #) = TopSpaceMetr (Euclid n)
by EUCLID:def 8;
then reconsider h = g as Function of I[01],(TopSpaceMetr (Euclid n)) ;
reconsider f = h as Function of (Closed-Interval-MSpace (0,1)),(Euclid n) by Lm3, EUCLID:67;
A8:
dom g = the carrier of I[01]
by FUNCT_2:def 1;
h is continuous
by A5, A7, PRE_TOPC:33;
then
f is uniformly_continuous
by Lm1, Th7, TOPMETR:20;
then consider s1 being Real such that
A9:
0 < s1
and
A10:
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;
set s = min (s1,(1 / 2));
defpred S1[ Nat, object ] means $2 = ((min (s1,(1 / 2))) / 2) * ($1 - 1);
A11:
0 <= min (s1,(1 / 2))
by A9, XXREAL_0:20;
then reconsider j = [/(2 / (min (s1,(1 / 2))))\] as Element of NAT by INT_1:53;
A12:
2 / (min (s1,(1 / 2))) <= j
by INT_1:def 7;
A13:
min (s1,(1 / 2)) <= s1
by XXREAL_0:17;
A14:
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 A13, XXREAL_0:2;
hence
dist (
(f /. u1),
(f /. u2))
< e / 2
by A10;
verum
end;
A15:
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 A16:
((min (s1,(1 / 2))) / 2) * (1 + ((2 / (min (s1,(1 / 2)))) - j)) <= ((min (s1,(1 / 2))) / 2) * 1
by A11, XREAL_1:64;
A17:
for k being Nat st k in Seg j holds
ex x being object st S1[k,x]
;
consider p being FinSequence such that
A18:
( dom p = Seg j & ( for k being Nat st k in Seg j holds
S1[k,p . k] ) )
from FINSEQ_1:sch 1(A17);
A19:
Seg (len p) = Seg j
by A18, FINSEQ_1:def 3;
rng (p ^ <*1*>) c= REAL
then reconsider h1 = p ^ <*1*> as FinSequence of REAL by FINSEQ_1:def 4;
A30: len h1 =
(len p) + (len <*1*>)
by FINSEQ_1:22
.=
(len p) + 1
by FINSEQ_1:40
;
A31:
len p = j
by A18, FINSEQ_1:def 3;
A32:
min (s1,(1 / 2)) <> 0
by A9, XXREAL_0:15;
then
2 / (min (s1,(1 / 2))) >= 2 / (1 / 2)
by A11, XREAL_1:118, XXREAL_0:17;
then
4 <= j
by A12, XXREAL_0:2;
then A33:
4 + 1 <= (len p) + 1
by A31, XREAL_1:6;
A34:
(min (s1,(1 / 2))) / 2 > 0
by A11, A32, XREAL_1:215;
A35:
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 A36:
( 1
<= i &
i < len p )
and A37:
r1 = p . i
and A38:
r2 = p . (i + 1)
;
( r1 < r2 & r2 - r1 = (min (s1,(1 / 2))) / 2 )
( 1
< i + 1 &
i + 1
<= len p )
by A36, NAT_1:13;
then
i + 1
in Seg j
by A19, FINSEQ_1:1;
then A39:
r2 = ((min (s1,(1 / 2))) / 2) * ((i + 1) - 1)
by A18, A38;
i < i + 1
by NAT_1:13;
then A40:
i - 1
< (i + 1) - 1
by XREAL_1:9;
A41:
i in Seg j
by A19, A36, FINSEQ_1:1;
then
r1 = ((min (s1,(1 / 2))) / 2) * (i - 1)
by A18, A37;
hence
r1 < r2
by A34, A39, A40, 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 A18, A37, A41, A39
.=
(min (s1,(1 / 2))) / 2
;
hence
r2 - r1 = (min (s1,(1 / 2))) / 2
;
verum
end;
0 < min (s1,(1 / 2))
by A9, XXREAL_0:15;
then
0 < j
by A15, XREAL_1:139;
then A42:
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 A18
.=
0
;
then A43:
h1 . 1 = 0
by A42, A31, Lm5;
2 * (min (s1,(1 / 2))) <> 0
by A9, XXREAL_0:15;
then A44:
( ((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 A45:
1 - (((min (s1,(1 / 2))) / 2) * (j - 1)) = ((min (s1,(1 / 2))) / 2) * (1 + ((2 / (min (s1,(1 / 2)))) - [/(2 / (min (s1,(1 / 2))))\]))
;
A46:
for r1 being Real st r1 = p . (len p) holds
1 - r1 <= (min (s1,(1 / 2))) / 2
by A42, A31, FINSEQ_1:1, A16, A18, A45;
A47:
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 A48:
1
<= i
and A49:
i < len h1
;
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
A50:
i + 1
<= len h1
by A49, NAT_1:13;
A51:
1
< i + 1
by A48, NAT_1:13;
A52:
i <= len p
by A30, A49, NAT_1:13;
now ( ( i < len p & (h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2 ) or ( i >= len p & (h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2 ) )per cases
( i < len p or i >= len p )
;
case A53:
i < len p
;
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2then
i + 1
<= len p
by NAT_1:13;
then A54:
h1 . (i + 1) = p . (i + 1)
by A51, FINSEQ_1:64;
A55:
h1 . i = p . i
by A48, A53, FINSEQ_1:64;
(
h1 . i = h1 /. i &
h1 . (i + 1) = h1 /. (i + 1) )
by A48, A49, A50, A51, FINSEQ_4:15;
hence
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
by A35, A48, A53, A55, A54;
verum end; case
i >= len p
;
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2then A56:
i = len p
by A52, XXREAL_0:1;
A57:
h1 /. i =
h1 . i
by A48, A49, FINSEQ_4:15
.=
p . i
by A48, A52, FINSEQ_1:64
;
h1 /. (i + 1) =
h1 . (i + 1)
by A50, A51, FINSEQ_4:15
.=
1
by A56, Lm4
;
hence
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
by A46, A56, A57;
verum end; end; end;
hence
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
;
verum
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 A58:
((min (s1,(1 / 2))) / 2) * (j - 1) < ((min (s1,(1 / 2))) / 2) * (2 / (min (s1,(1 / 2))))
by A34, XREAL_1:68;
A59:
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 A60:
1
<= i
and A61:
i <= len p
and A62:
r1 = p . i
;
r1 < 1
i - 1
<= j - 1
by A31, A61, XREAL_1:9;
then A63:
((min (s1,(1 / 2))) / 2) * (i - 1) <= ((min (s1,(1 / 2))) / 2) * (j - 1)
by A11, XREAL_1:64;
i in Seg j
by A19, A60, A61, FINSEQ_1:1;
then
r1 = ((min (s1,(1 / 2))) / 2) * (i - 1)
by A18, A62;
hence
r1 < 1
by A58, A44, A63, XXREAL_0:2;
verum
end;
A64:
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 A65:
1
<= i
and A66:
i < len h1
;
h1 /. i < h1 /. (i + 1)
A67:
1
< i + 1
by A65, NAT_1:13;
A68:
i <= len p
by A30, A66, NAT_1:13;
A69:
i + 1
<= len h1
by A66, NAT_1:13;
per cases
( i < len p or i >= len p )
;
suppose A70:
i < len p
;
h1 /. i < h1 /. (i + 1)then
i + 1
<= len p
by NAT_1:13;
then A71:
h1 . (i + 1) = p . (i + 1)
by A67, FINSEQ_1:64;
A72:
h1 . i = p . i
by A65, A70, FINSEQ_1:64;
(
h1 . i = h1 /. i &
h1 . (i + 1) = h1 /. (i + 1) )
by A65, A66, A69, A67, FINSEQ_4:15;
hence
h1 /. i < h1 /. (i + 1)
by A35, A65, A70, A72, A71;
verum end; suppose
i >= len p
;
h1 /. i < h1 /. (i + 1)then A73:
i = len p
by A68, XXREAL_0:1;
A74:
h1 /. i =
h1 . i
by A65, A66, FINSEQ_4:15
.=
p . i
by A65, A68, FINSEQ_1:64
;
h1 /. (i + 1) =
h1 . (i + 1)
by A69, A67, FINSEQ_4:15
.=
1
by A73, Lm4
;
hence
h1 /. i < h1 /. (i + 1)
by A59, A65, A68, A74;
verum end; end;
end;
A75:
e / 2 < e
by A4, XREAL_1:216;
A76:
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 A77:
( 1
<= i &
i < len h1 )
and A78:
Q = [.(h1 /. i),(h1 /. (i + 1)).]
and A79:
W = g .: Q
;
diameter W < e
h1 /. i < h1 /. (i + 1)
by A64, A77;
then A80:
Q <> {}
by A78, XXREAL_1:1;
A81:
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 A82:
x in W
and A83:
y in W
;
dist (x,y) <= e / 2
consider x3 being
object such that A84:
x3 in dom g
and A85:
x3 in Q
and A86:
x = g . x3
by A79, A82, FUNCT_1:def 6;
reconsider x3 =
x3 as
Element of
(Closed-Interval-MSpace (0,1)) by A84, Lm2, TOPMETR:12;
reconsider r3 =
x3 as
Real by A78, A85;
A87:
(h1 /. (i + 1)) - (h1 /. i) <= (min (s1,(1 / 2))) / 2
by A47, A77;
consider y3 being
object such that A88:
y3 in dom g
and A89:
y3 in Q
and A90:
y = g . y3
by A79, A83, FUNCT_1:def 6;
reconsider y3 =
y3 as
Element of
(Closed-Interval-MSpace (0,1)) by A88, Lm2, TOPMETR:12;
reconsider s3 =
y3 as
Real by A78, A89;
A91:
(
f . x3 = f /. x3 &
f . y3 = f /. y3 )
;
|.(r3 - s3).| <= (h1 /. (i + 1)) - (h1 /. i)
by A78, A85, A89, Th12;
then
|.(r3 - s3).| <= (min (s1,(1 / 2))) / 2
by A87, XXREAL_0:2;
then A92:
dist (
x3,
y3)
<= (min (s1,(1 / 2))) / 2
by HEINE:1;
(min (s1,(1 / 2))) / 2
< min (
s1,
(1 / 2))
by A11, A32, XREAL_1:216;
then
dist (
x3,
y3)
< min (
s1,
(1 / 2))
by A92, XXREAL_0:2;
hence
dist (
x,
y)
<= e / 2
by A14, A86, A90, A91;
verum
end;
then
W is
bounded
by A6, TBSP_1:def 7;
then
diameter W <= e / 2
by A8, A79, A80, A81, TBSP_1:def 8;
hence
diameter W < e
by A75, XXREAL_0:2;
verum
end;
A93:
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 A94:
x in dom p
and A95:
y = p . x
by FUNCT_1:def 3;
reconsider nx =
x as
Element of
NAT by A94;
A96:
p . nx = ((min (s1,(1 / 2))) / 2) * (nx - 1)
by A18, A94;
then reconsider ry =
p . nx as
Real ;
A97:
x in Seg (len p)
by A94, FINSEQ_1:def 3;
then A98:
1
<= nx
by FINSEQ_1:1;
then A99:
nx - 1
>= 1
- 1
by XREAL_1:9;
nx <= len p
by A97, FINSEQ_1:1;
then
ry < 1
by A59, A98;
then
y in { rs where rs is Real : ( 0 <= rs & rs <= 1 ) }
by A11, A95, A96, A99;
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 A100:
rng h1 c= [.0,1.] \/ {1}
by A93, XBOOLE_1:13;
h1 . (len h1) = 1
by A30, Lm4;
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 A30, A33, A43, A2, A100, A3, A64, A76, Lm7; verum