let n be non zero Nat; for f being PartFunc of [:(CarProduct ((Seg n) --> RNS_Real)),RNS_Real:],RNS_Real
for g being PartFunc of [:(CarProduct ((Seg n) --> REAL)),REAL:],REAL
for P2 being PartFunc of (CarProduct ((Seg n) --> RNS_Real)),RNS_Real
for q being Element of REAL st f is_continuous_on dom f & f = g & P2 = ProjPMap2 (g,q) holds
P2 is_continuous_on dom P2
let f be PartFunc of [:(CarProduct ((Seg n) --> RNS_Real)),RNS_Real:],RNS_Real; for g being PartFunc of [:(CarProduct ((Seg n) --> REAL)),REAL:],REAL
for P2 being PartFunc of (CarProduct ((Seg n) --> RNS_Real)),RNS_Real
for q being Element of REAL st f is_continuous_on dom f & f = g & P2 = ProjPMap2 (g,q) holds
P2 is_continuous_on dom P2
let g be PartFunc of [:(CarProduct ((Seg n) --> REAL)),REAL:],REAL; for P2 being PartFunc of (CarProduct ((Seg n) --> RNS_Real)),RNS_Real
for q being Element of REAL st f is_continuous_on dom f & f = g & P2 = ProjPMap2 (g,q) holds
P2 is_continuous_on dom P2
let P2 be PartFunc of (CarProduct ((Seg n) --> RNS_Real)),RNS_Real; for q being Element of REAL st f is_continuous_on dom f & f = g & P2 = ProjPMap2 (g,q) holds
P2 is_continuous_on dom P2
let q be Element of REAL ; ( f is_continuous_on dom f & f = g & P2 = ProjPMap2 (g,q) implies P2 is_continuous_on dom P2 )
assume that
A1:
f is_continuous_on dom f
and
A2:
f = g
and
A3:
P2 = ProjPMap2 (g,q)
; P2 is_continuous_on dom P2
for x0 being Point of (CarProduct ((Seg n) --> RNS_Real)) st x0 in dom P2 holds
P2 is_continuous_in x0
proof
let x0 be
Point of
(CarProduct ((Seg n) --> RNS_Real));
( x0 in dom P2 implies P2 is_continuous_in x0 )
assume A4:
x0 in dom P2
;
P2 is_continuous_in x0
then A5:
x0 in Y-section (
(dom g),
q)
by A3, MESFUN12:def 4;
A6:
Y-section (
(dom g),
q)
= { x where x is Element of CarProduct ((Seg n) --> REAL) : [x,q] in dom g }
by MEASUR11:def 5;
then A7:
ex
x being
Element of
CarProduct ((Seg n) --> REAL) st
(
x = x0 &
[x,q] in dom g )
by A5;
reconsider yy =
q as
Point of
RNS_Real ;
reconsider xx0 =
x0 as
Point of
(CarProduct ((Seg n) --> RNS_Real)) ;
reconsider p0 =
[xx0,yy] as
Point of
[:(CarProduct ((Seg n) --> RNS_Real)),RNS_Real:] ;
for
r being
Real st
0 < r holds
ex
s being
Real st
(
0 < s & ( for
x1 being
Point of
(CarProduct ((Seg n) --> RNS_Real)) st
x1 in dom P2 &
||.(x1 - x0).|| < s holds
||.((P2 /. x1) - (P2 /. x0)).|| < r ) )
proof
let r be
Real;
( 0 < r implies ex s being Real st
( 0 < s & ( for x1 being Point of (CarProduct ((Seg n) --> RNS_Real)) st x1 in dom P2 & ||.(x1 - x0).|| < s holds
||.((P2 /. x1) - (P2 /. x0)).|| < r ) ) )
assume
0 < r
;
ex s being Real st
( 0 < s & ( for x1 being Point of (CarProduct ((Seg n) --> RNS_Real)) st x1 in dom P2 & ||.(x1 - x0).|| < s holds
||.((P2 /. x1) - (P2 /. x0)).|| < r ) )
then consider s0 being
Real such that A8:
0 < s0
and A9:
for
p1 being
Point of
[:(CarProduct ((Seg n) --> RNS_Real)),RNS_Real:] st
p1 in dom f &
||.(p1 - p0).|| < s0 holds
||.((f /. p1) - (f /. p0)).|| < r
by A1, A2, A7, NFCONT_1:19;
now for x1 being Point of (CarProduct ((Seg n) --> RNS_Real)) st x1 in dom P2 & ||.(x1 - x0).|| < s0 holds
||.((P2 /. x1) - (P2 /. x0)).|| < rlet x1 be
Point of
(CarProduct ((Seg n) --> RNS_Real));
( x1 in dom P2 & ||.(x1 - x0).|| < s0 implies ||.((P2 /. x1) - (P2 /. x0)).|| < r )assume that A10:
x1 in dom P2
and A11:
||.(x1 - x0).|| < s0
;
||.((P2 /. x1) - (P2 /. x0)).|| < r
x1 in Y-section (
(dom g),
q)
by A3, A10, MESFUN12:def 4;
then A12:
ex
x being
Element of
CarProduct ((Seg n) --> REAL) st
(
x = x1 &
[x,q] in dom g )
by A6;
reconsider xx1 =
x1 as
Point of
(CarProduct ((Seg n) --> RNS_Real)) ;
reconsider p1 =
[xx1,yy] as
Point of
[:(CarProduct ((Seg n) --> RNS_Real)),RNS_Real:] ;
p1 - p0 = [xx1,yy] + [(- xx0),(- yy)]
by PRVECT_3:18;
then
p1 - p0 = [(xx1 - xx0),(yy - yy)]
by PRVECT_3:18;
then
p1 - p0 = [(xx1 - xx0),(0. RNS_Real)]
by RLVECT_1:15;
then
||.(p1 - p0).|| = sqrt ((||.(0. RNS_Real).|| ^2) + (||.(xx1 - xx0).|| ^2))
by NDIFF_8:1;
then A13:
||.(p1 - p0).|| = ||.(xx1 - xx0).||
by SQUARE_1:22;
(
P2 . x1 = g . (
x1,
q) &
P2 . x0 = g . (
x0,
q) )
by A3, A7, A12, MESFUN12:def 4;
then
(
P2 . x1 = f /. p1 &
P2 . x0 = f /. p0 )
by A2, A7, A12, PARTFUN1:def 6;
then
(
P2 /. x1 = f /. p1 &
P2 /. x0 = f /. p0 )
by A4, A10, PARTFUN1:def 6;
hence
||.((P2 /. x1) - (P2 /. x0)).|| < r
by A11, A2, A12, A9, A13;
verum end;
hence
ex
s being
Real st
(
0 < s & ( for
x1 being
Point of
(CarProduct ((Seg n) --> RNS_Real)) st
x1 in dom P2 &
||.(x1 - x0).|| < s holds
||.((P2 /. x1) - (P2 /. x0)).|| < r ) )
by A8;
verum
end;
hence
P2 is_continuous_in x0
by A4, NFCONT_1:7;
verum
end;
hence
P2 is_continuous_on dom P2
; verum