let r be real number ; :: thesis: for X being set
for F, f being PartFunc of REAL ,REAL st F is_integral_of f,X holds
r (#) F is_integral_of r (#) f,X
let X be set ; :: thesis: for F, f being PartFunc of REAL ,REAL st F is_integral_of f,X holds
r (#) F is_integral_of r (#) f,X
let F, f be PartFunc of REAL ,REAL ; :: thesis: ( F is_integral_of f,X implies r (#) F is_integral_of r (#) f,X )
assume
F is_integral_of f,X
; :: thesis: r (#) F is_integral_of r (#) f,X
then A1:
( F is_differentiable_on X & F `| X = f | X )
by Lm1;
then A2:
r (#) F is_differentiable_on X
by Th7;
dom (f | X) = X
by A1, FDIFF_1:def 8;
then
(dom f) /\ X = X
by RELAT_1:90;
then
X c= dom f
by XBOOLE_1:18;
then A3:
X c= dom (r (#) f)
by VALUED_1:def 5;
then
X = dom ((r (#) f) | X)
by RELAT_1:91;
then A4:
dom ((r (#) F) `| X) = dom ((r (#) f) | X)
by A2, FDIFF_1:def 8;
now let x be
Element of
REAL ;
:: thesis: ( x in dom ((r (#) F) `| X) implies ((r (#) F) `| X) . x = ((r (#) f) | X) . x )assume
x in dom ((r (#) F) `| X)
;
:: thesis: ((r (#) F) `| X) . x = ((r (#) f) | X) . xthen A5:
x in X
by A2, FDIFF_1:def 8;
then A6:
((r (#) F) `| X) . x = diff (r (#) F),
x
by A2, FDIFF_1:def 8;
reconsider r1 =
r as
Real by XREAL_0:def 1;
F | X is_differentiable_in x
by A1, A5, FDIFF_1:def 7;
then
F is_differentiable_in x
by A5, Th4;
then A7:
((r1 (#) F) `| X) . x = r1 * (diff F,x)
by A6, FDIFF_1:23;
(F `| X) . x = diff F,
x
by A1, A5, FDIFF_1:def 8;
then
f . x = diff F,
x
by A1, A5, FUNCT_1:72;
then
((r (#) F) `| X) . x = (r (#) f) . x
by A3, A5, A7, VALUED_1:def 5;
hence
((r (#) F) `| X) . x = ((r (#) f) | X) . x
by A5, FUNCT_1:72;
:: thesis: verum end;
then
(r (#) F) `| X = (r (#) f) | X
by A4, PARTFUN1:34;
hence
r (#) F is_integral_of r (#) f,X
by A2, Lm1; :: thesis: verum