let A be closed-interval Subset of REAL ; :: thesis: integral ((AffineMap 1,0 ) (#) exp_R ),A = ((exp_R (#) (AffineMap 1,(- 1))) . (upper_bound A)) - ((exp_R (#) (AffineMap 1,(- 1))) . (lower_bound A))
A1:
dom (exp_R (#) (AffineMap 1,(- 1))) = [#] REAL
by FUNCT_2:def 1;
A2:
dom (AffineMap 1,0 ) = [#] REAL
by FUNCT_2:def 1;
B1:
[#] REAL = dom ((AffineMap 1,0 ) (#) exp_R )
by FUNCT_2:def 1;
A3:
for x being Real st x in REAL holds
(AffineMap 1,(- 1)) . x = x - 1
A4:
for x being Real st x in REAL holds
(AffineMap 1,0 ) . x = (1 * x) + 0
by JORDAN16:def 3;
C1:
AffineMap 1,0 is_differentiable_on REAL
by A2, A4, FDIFF_1:31;
(AffineMap 1,0 ) (#) exp_R is_differentiable_on REAL
by B1, C1, FDIFF_1:29, TAYLOR_1:16;
then
((AffineMap 1,0 ) (#) exp_R ) | REAL is continuous
by FDIFF_1:33;
then
((AffineMap 1,0 ) (#) exp_R ) | A is continuous
by FCONT_1:17;
then A5:
( (AffineMap 1,0 ) (#) exp_R is_integrable_on A & ((AffineMap 1,0 ) (#) exp_R ) | A is bounded )
by B1, INTEGRA5:10, INTEGRA5:11;
A6:
exp_R (#) (AffineMap 1,(- 1)) is_differentiable_on REAL
by A1, A3, FDIFF_4:55;
B:
for x being Real st x in REAL holds
((AffineMap 1,0 ) (#) exp_R ) . x = x * (exp_R . x)
A7:
for x being Real st x in dom ((exp_R (#) (AffineMap 1,(- 1))) `| REAL ) holds
((exp_R (#) (AffineMap 1,(- 1))) `| REAL ) . x = ((AffineMap 1,0 ) (#) exp_R ) . x
proof
let x be
Real;
:: thesis: ( x in dom ((exp_R (#) (AffineMap 1,(- 1))) `| REAL ) implies ((exp_R (#) (AffineMap 1,(- 1))) `| REAL ) . x = ((AffineMap 1,0 ) (#) exp_R ) . x )
assume
x in dom ((exp_R (#) (AffineMap 1,(- 1))) `| REAL )
;
:: thesis: ((exp_R (#) (AffineMap 1,(- 1))) `| REAL ) . x = ((AffineMap 1,0 ) (#) exp_R ) . x
((exp_R (#) (AffineMap 1,(- 1))) `| REAL ) . x =
x * (exp_R . x)
by A1, A3, FDIFF_4:55
.=
((AffineMap 1,0 ) (#) exp_R ) . x
by B
;
hence
((exp_R (#) (AffineMap 1,(- 1))) `| REAL ) . x = ((AffineMap 1,0 ) (#) exp_R ) . x
;
:: thesis: verum
end;
dom ((exp_R (#) (AffineMap 1,(- 1))) `| REAL ) = dom ((AffineMap 1,0 ) (#) exp_R )
by B1, A6, FDIFF_1:def 8;
then
(exp_R (#) (AffineMap 1,(- 1))) `| REAL = (AffineMap 1,0 ) (#) exp_R
by A7, PARTFUN1:34;
hence
integral ((AffineMap 1,0 ) (#) exp_R ),A = ((exp_R (#) (AffineMap 1,(- 1))) . (upper_bound A)) - ((exp_R (#) (AffineMap 1,(- 1))) . (lower_bound A))
by A1, A3, A5, FDIFF_4:55, INTEGRA5:13; :: thesis: verum