let a, b be Real; :: thesis: for n being Element of NAT
for A being closed-interval Subset of REAL st a * (n + 1) <> 0 holds
integral ((#Z n) * (AffineMap a,b)),A = (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (sup A)) - (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (inf A))
let n be Element of NAT ; :: thesis: for A being closed-interval Subset of REAL st a * (n + 1) <> 0 holds
integral ((#Z n) * (AffineMap a,b)),A = (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (sup A)) - (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (inf A))
let A be closed-interval Subset of REAL ; :: thesis: ( a * (n + 1) <> 0 implies integral ((#Z n) * (AffineMap a,b)),A = (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (sup A)) - (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (inf A)) )
assume C:
a * (n + 1) <> 0
; :: thesis: integral ((#Z n) * (AffineMap a,b)),A = (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (sup A)) - (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (inf A))
A1:
( [#] REAL = dom ((#Z n) * (AffineMap a,b)) & [#] REAL = dom ((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) & [#] REAL = dom (AffineMap a,b) )
by FUNCT_2:def 1;
for x being Real st x in REAL holds
(AffineMap a,b) . x = (a * x) + b
by JORDAN16:def 3;
then B1:
( AffineMap a,b is_differentiable_on REAL & ( for x being Real st x in [#] REAL holds
((AffineMap a,b) `| REAL ) . x = a ) )
by A1, FDIFF_1:31;
A:
for x being Real holds (#Z n) * (AffineMap a,b) is_differentiable_in x
A2:
(#Z n) * (AffineMap a,b) is_differentiable_on REAL
((#Z n) * (AffineMap a,b)) | REAL is continuous
by A2, FDIFF_1:33;
then
((#Z n) * (AffineMap a,b)) | A is continuous
by FCONT_1:17;
then A3:
( (#Z n) * (AffineMap a,b) is_integrable_on A & ((#Z n) * (AffineMap a,b)) | A is bounded )
by A1, INTEGRA5:10, INTEGRA5:11;
A4:
for x being Real st x in dom (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL ) holds
(((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL ) . x = ((#Z n) * (AffineMap a,b)) . x
proof
let x be
Real;
:: thesis: ( x in dom (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL ) implies (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL ) . x = ((#Z n) * (AffineMap a,b)) . x )
assume
x in dom (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL )
;
:: thesis: (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL ) . x = ((#Z n) * (AffineMap a,b)) . x
(((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL ) . x =
((a * x) + b) #Z n
by C, Th12
.=
((AffineMap a,b) . x) #Z n
by JORDAN16:def 3
.=
(#Z n) . ((AffineMap a,b) . x)
by TAYLOR_1:def 1
.=
((#Z n) * (AffineMap a,b)) . x
by A1, FUNCT_1:23
;
hence
(((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL ) . x = ((#Z n) * (AffineMap a,b)) . x
;
:: thesis: verum
end;
(1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b)) is_differentiable_on REAL
by C, Th12;
then
dom (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL ) = dom ((#Z n) * (AffineMap a,b))
by A1, FDIFF_1:def 8;
then
((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) `| REAL = (#Z n) * (AffineMap a,b)
by A4, PARTFUN1:34;
hence
integral ((#Z n) * (AffineMap a,b)),A = (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (sup A)) - (((1 / (a * (n + 1))) (#) ((#Z (n + 1)) * (AffineMap a,b))) . (inf A))
by C, A3, Th12, INTEGRA5:13; :: thesis: verum