let f be PartFunc of [:[:RNS_Real,RNS_Real:],RNS_Real:],RNS_Real; for g being PartFunc of [:[:REAL,REAL:],REAL:],REAL
for E being set st f = g & E c= dom f holds
( f is_uniformly_continuous_on E iff for e being Real st 0 < e holds
ex r being Real st
( 0 < r & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r & |.(y2 - y1).| < r & |.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) ) )
let g be PartFunc of [:[:REAL,REAL:],REAL:],REAL; for E being set st f = g & E c= dom f holds
( f is_uniformly_continuous_on E iff for e being Real st 0 < e holds
ex r being Real st
( 0 < r & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r & |.(y2 - y1).| < r & |.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) ) )
let E be set ; ( f = g & E c= dom f implies ( f is_uniformly_continuous_on E iff for e being Real st 0 < e holds
ex r being Real st
( 0 < r & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r & |.(y2 - y1).| < r & |.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) ) ) )
assume that
A1:
f = g
and
A2:
E c= dom f
; ( f is_uniformly_continuous_on E iff for e being Real st 0 < e holds
ex r being Real st
( 0 < r & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r & |.(y2 - y1).| < r & |.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) ) )
hereby ( ( for e being Real st 0 < e holds
ex r being Real st
( 0 < r & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r & |.(y2 - y1).| < r & |.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) ) ) implies f is_uniformly_continuous_on E )
assume A3:
f is_uniformly_continuous_on E
;
for e being Real st 0 < e holds
ex r being Real st
( 0 < r & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r & |.(y2 - y1).| < r & |.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) )thus
for
e being
Real st
0 < e holds
ex
r being
Real st
(
0 < r & ( for
x1,
x2,
y1,
y2,
z1,
z2 being
Real st
[x1,y1,z1] in E &
[x2,y2,z2] in E &
|.(x2 - x1).| < r &
|.(y2 - y1).| < r &
|.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) )
verumproof
let e be
Real;
( 0 < e implies ex r being Real st
( 0 < r & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r & |.(y2 - y1).| < r & |.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) ) )
assume
0 < e
;
ex r being Real st
( 0 < r & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r & |.(y2 - y1).| < r & |.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) )
then consider r being
Real such that A4:
(
0 < r & ( for
p1,
p2 being
Point of
[:[:RNS_Real,RNS_Real:],RNS_Real:] st
p1 in E &
p2 in E &
||.(p1 - p2).|| < r holds
||.((f /. p1) - (f /. p2)).|| < e ) )
by A3;
set r1 =
r / 3;
take
r / 3
;
( 0 < r / 3 & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r / 3 & |.(y2 - y1).| < r / 3 & |.(z2 - z1).| < r / 3 holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) )
thus
0 < r / 3
by A4, XREAL_1:222;
for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r / 3 & |.(y2 - y1).| < r / 3 & |.(z2 - z1).| < r / 3 holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e
let x1,
x2,
y1,
y2,
z1,
z2 be
Real;
( [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r / 3 & |.(y2 - y1).| < r / 3 & |.(z2 - z1).| < r / 3 implies |.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e )
assume A5:
(
[x1,y1,z1] in E &
[x2,y2,z2] in E &
|.(x2 - x1).| < r / 3 &
|.(y2 - y1).| < r / 3 &
|.(z2 - z1).| < r / 3 )
;
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e
reconsider xx1 =
x1,
yy1 =
y1,
zz1 =
z1,
xx2 =
x2,
yy2 =
y2,
zz2 =
z2 as
Point of
RNS_Real by XREAL_0:def 1;
reconsider p1 =
[xx1,yy1,zz1],
p2 =
[xx2,yy2,zz2] as
Point of
[:[:RNS_Real,RNS_Real:],RNS_Real:] ;
- p2 = [(- xx2),(- yy2),(- zz2)]
by PRVECT_4:9;
then A6:
p1 - p2 = [(xx1 - xx2),(yy1 - yy2),(zz1 - zz2)]
by PRVECT_4:9;
A7:
(
xx1 - xx2 = x1 - x2 &
yy1 - yy2 = y1 - y2 &
zz1 - zz2 = z1 - z2 )
by DUALSP03:4;
then
||.(xx1 - xx2).|| = |.(x1 - x2).|
by EUCLID:def 2;
then A8:
||.(xx1 - xx2).|| = |.(x2 - x1).|
by COMPLEX1:60;
||.(yy1 - yy2).|| = |.(y1 - y2).|
by A7, EUCLID:def 2;
then A9:
||.(yy1 - yy2).|| = |.(y2 - y1).|
by COMPLEX1:60;
||.(zz1 - zz2).|| = |.(z1 - z2).|
by A7, EUCLID:def 2;
then
||.(zz1 - zz2).|| = |.(z2 - z1).|
by COMPLEX1:60;
then A10:
||.(p1 - p2).|| <= (|.(x2 - x1).| + |.(y2 - y1).|) + |.(z2 - z1).|
by A6, A8, A9, Th1;
|.(x2 - x1).| + |.(y2 - y1).| < (r / 3) + (r / 3)
by A5, XREAL_1:8;
then
(|.(x2 - x1).| + |.(y2 - y1).|) + |.(z2 - z1).| < ((r / 3) + (r / 3)) + (r / 3)
by A5, XREAL_1:8;
then
||.(p1 - p2).|| < ((r / 3) + (r / 3)) + (r / 3)
by A10, XXREAL_0:2;
then A11:
||.((f /. p1) - (f /. p2)).|| < e
by A4, A5;
A12:
f /. p1 = g . [x1,y1,z1]
by A1, A2, A5, PARTFUN1:def 6;
f /. p2 = f . p2
by A2, A5, PARTFUN1:def 6;
then
(f /. p1) - (f /. p2) = (g . [x1,y1,z1]) - (g . [x2,y2,z2])
by A1, A12, DUALSP03:4;
then
||.((f /. p1) - (f /. p2)).|| = |.((g . [x1,y1,z1]) - (g . [x2,y2,z2])).|
by EUCLID:def 2;
hence
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e
by A11, COMPLEX1:60;
verum
end;
end;
assume A13:
for e being Real st 0 < e holds
ex r being Real st
( 0 < r & ( for x1, x2, y1, y2, z1, z2 being Real st [x1,y1,z1] in E & [x2,y2,z2] in E & |.(x2 - x1).| < r & |.(y2 - y1).| < r & |.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) )
; f is_uniformly_continuous_on E
for e being Real st 0 < e holds
ex r being Real st
( 0 < r & ( for p1, p2 being Point of [:[:RNS_Real,RNS_Real:],RNS_Real:] st p1 in E & p2 in E & ||.(p1 - p2).|| < r holds
||.((f /. p1) - (f /. p2)).|| < e ) )
proof
let e be
Real;
( 0 < e implies ex r being Real st
( 0 < r & ( for p1, p2 being Point of [:[:RNS_Real,RNS_Real:],RNS_Real:] st p1 in E & p2 in E & ||.(p1 - p2).|| < r holds
||.((f /. p1) - (f /. p2)).|| < e ) ) )
assume
0 < e
;
ex r being Real st
( 0 < r & ( for p1, p2 being Point of [:[:RNS_Real,RNS_Real:],RNS_Real:] st p1 in E & p2 in E & ||.(p1 - p2).|| < r holds
||.((f /. p1) - (f /. p2)).|| < e ) )
then consider r being
Real such that A14:
(
0 < r & ( for
x1,
x2,
y1,
y2,
z1,
z2 being
Real st
[x1,y1,z1] in E &
[x2,y2,z2] in E &
|.(x2 - x1).| < r &
|.(y2 - y1).| < r &
|.(z2 - z1).| < r holds
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e ) )
by A13;
take
r
;
( 0 < r & ( for p1, p2 being Point of [:[:RNS_Real,RNS_Real:],RNS_Real:] st p1 in E & p2 in E & ||.(p1 - p2).|| < r holds
||.((f /. p1) - (f /. p2)).|| < e ) )
thus
0 < r
by A14;
for p1, p2 being Point of [:[:RNS_Real,RNS_Real:],RNS_Real:] st p1 in E & p2 in E & ||.(p1 - p2).|| < r holds
||.((f /. p1) - (f /. p2)).|| < e
thus
for
p1,
p2 being
Point of
[:[:RNS_Real,RNS_Real:],RNS_Real:] st
p1 in E &
p2 in E &
||.(p1 - p2).|| < r holds
||.((f /. p1) - (f /. p2)).|| < e
verumproof
let p1,
p2 be
Point of
[:[:RNS_Real,RNS_Real:],RNS_Real:];
( p1 in E & p2 in E & ||.(p1 - p2).|| < r implies ||.((f /. p1) - (f /. p2)).|| < e )
assume that A15:
(
p1 in E &
p2 in E )
and A16:
||.(p1 - p2).|| < r
;
||.((f /. p1) - (f /. p2)).|| < e
A17:
(
p1 is
Point of
[:RNS_Real,RNS_Real,RNS_Real:] &
p2 is
Point of
[:RNS_Real,RNS_Real,RNS_Real:] )
;
then consider xx1,
yy1,
zz1 being
Point of
RNS_Real such that A18:
p1 = [xx1,yy1,zz1]
by PRVECT_4:9;
consider xx2,
yy2,
zz2 being
Point of
RNS_Real such that A19:
p2 = [xx2,yy2,zz2]
by A17, PRVECT_4:9;
reconsider x1 =
xx1,
y1 =
yy1,
z1 =
zz1,
x2 =
xx2,
y2 =
yy2,
z2 =
zz2 as
Real ;
- p2 = [(- xx2),(- yy2),(- zz2)]
by A19, PRVECT_4:9;
then A20:
p1 - p2 = [(xx1 - xx2),(yy1 - yy2),(zz1 - zz2)]
by A18, PRVECT_4:9;
A21:
(
xx1 - xx2 = x1 - x2 &
yy1 - yy2 = y1 - y2 &
zz1 - zz2 = z1 - z2 )
by DUALSP03:4;
then
||.(xx1 - xx2).|| = |.(x1 - x2).|
by EUCLID:def 2;
then A22:
||.(xx1 - xx2).|| = |.(x2 - x1).|
by COMPLEX1:60;
||.(yy1 - yy2).|| = |.(y1 - y2).|
by A21, EUCLID:def 2;
then A23:
||.(yy1 - yy2).|| = |.(y2 - y1).|
by COMPLEX1:60;
||.(zz1 - zz2).|| = |.(z1 - z2).|
by A21, EUCLID:def 2;
then
||.(zz1 - zz2).|| = |.(z2 - z1).|
by COMPLEX1:60;
then
(
|.(x2 - x1).| <= ||.(p1 - p2).|| &
|.(y2 - y1).| <= ||.(p1 - p2).|| &
|.(z2 - z1).| <= ||.(p1 - p2).|| )
by A20, A22, A23, Th1;
then
(
|.(x2 - x1).| < r &
|.(y2 - y1).| < r &
|.(z2 - z1).| < r )
by A16, XXREAL_0:2;
then A24:
|.((g . [x2,y2,z2]) - (g . [x1,y1,z1])).| < e
by A14, A15, A18, A19;
A25:
f /. p1 = g . [x1,y1,z1]
by A1, A2, A15, A18, PARTFUN1:def 6;
f /. p2 = f . p2
by A2, A15, PARTFUN1:def 6;
then
(f /. p1) - (f /. p2) = (g . [x1,y1,z1]) - (g . [x2,y2,z2])
by A1, A19, A25, DUALSP03:4;
then
||.((f /. p1) - (f /. p2)).|| = |.((g . [x1,y1,z1]) - (g . [x2,y2,z2])).|
by EUCLID:def 2;
hence
||.((f /. p1) - (f /. p2)).|| < e
by A24, COMPLEX1:60;
verum
end;
end;
hence
f is_uniformly_continuous_on E
by A2; verum