let r be Real; 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 ; 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; ( F is_integral_of f,X implies r (#) F is_integral_of r (#) f,X )
assume A1:
F is_integral_of f,X
; r (#) F is_integral_of r (#) f,X
then A2:
F is_differentiable_on X
by Lm1;
then A3:
r (#) F is_differentiable_on X
by Th7;
A4:
F `| X = f | X
by A1, Lm1;
then
dom (f | X) = X
by A2, FDIFF_1:def 7;
then
(dom f) /\ X = X
by RELAT_1:61;
then
X c= dom f
by XBOOLE_1:18;
then A5:
X c= dom (r (#) f)
by VALUED_1:def 5;
A6:
now for x being Element of REAL st x in dom ((r (#) F) `| X) holds
((r (#) F) `| X) . x = ((r (#) f) | X) . xreconsider r1 =
r as
Real ;
let x be
Element of
REAL ;
( x in dom ((r (#) F) `| X) implies ((r (#) F) `| X) . x = ((r (#) f) | X) . x )assume
x in dom ((r (#) F) `| X)
;
((r (#) F) `| X) . x = ((r (#) f) | X) . xthen A7:
x in X
by A3, FDIFF_1:def 7;
then
F | X is_differentiable_in x
by A2;
then A8:
F is_differentiable_in x
by A7, Th4;
((r (#) F) `| X) . x = diff (
(r (#) F),
x)
by A3, A7, FDIFF_1:def 7;
then A9:
((r1 (#) F) `| X) . x = r1 * (diff (F,x))
by A8, FDIFF_1:15;
(F `| X) . x = diff (
F,
x)
by A2, A7, FDIFF_1:def 7;
then
f . x = diff (
F,
x)
by A4, A7, FUNCT_1:49;
then
((r (#) F) `| X) . x = (r (#) f) . x
by A5, A7, A9, VALUED_1:def 5;
hence
((r (#) F) `| X) . x = ((r (#) f) | X) . x
by A7, FUNCT_1:49;
verum end;
X = dom ((r (#) f) | X)
by A5, RELAT_1:62;
then
dom ((r (#) F) `| X) = dom ((r (#) f) | X)
by A3, FDIFF_1:def 7;
then
(r (#) F) `| X = (r (#) f) | X
by A6, PARTFUN1:5;
hence
r (#) F is_integral_of r (#) f,X
by A3, Lm1; verum