let A be closed-interval Subset of REAL ; :: thesis: for Z being open Subset of REAL st A c= Z holds
integral ((- (id Z)) (#) cos ),A = (((- cos ) - ((id Z) (#) sin )) . (upper_bound A)) - (((- cos ) - ((id Z) (#) sin )) . (lower_bound A))
let Z be open Subset of REAL ; :: thesis: ( A c= Z implies integral ((- (id Z)) (#) cos ),A = (((- cos ) - ((id Z) (#) sin )) . (upper_bound A)) - (((- cos ) - ((id Z) (#) sin )) . (lower_bound A)) )
assume A1:
A c= Z
; :: thesis: integral ((- (id Z)) (#) cos ),A = (((- cos ) - ((id Z) (#) sin )) . (upper_bound A)) - (((- cos ) - ((id Z) (#) sin )) . (lower_bound A))
A2:
Z = dom ((- (id Z)) (#) cos )
Z = (dom (- (id Z))) /\ (dom cos )
by A2, VALUED_1:def 4;
then AA:
( Z c= dom (- (id Z)) & Z c= dom cos )
by XBOOLE_1:18;
A3:
for x being Real st x in Z holds
(- (id Z)) . x = ((- 1) * x) + 0
B:
for x being Real st x in Z holds
((- (id Z)) (#) cos ) . x = - (x * (cos . x))
C:
- (id Z) is_differentiable_on Z
by AA, A3, FDIFF_1:31;
cos is_differentiable_on Z
by FDIFF_1:34, SIN_COS:72;
then
((- (id Z)) (#) cos ) | Z is continuous
by A2, C, FDIFF_1:29, FDIFF_1:33;
then
((- (id Z)) (#) cos ) | A is continuous
by A1, FCONT_1:17;
then A4:
( (- (id Z)) (#) cos is_integrable_on A & ((- (id Z)) (#) cos ) | A is bounded )
by A1, A2, INTEGRA5:10, INTEGRA5:11;
A5:
(- cos ) - ((id Z) (#) sin ) is_differentiable_on Z
by Th19;
A6:
for x being Real st x in dom (((- cos ) - ((id Z) (#) sin )) `| Z) holds
(((- cos ) - ((id Z) (#) sin )) `| Z) . x = ((- (id Z)) (#) cos ) . x
dom (((- cos ) - ((id Z) (#) sin )) `| Z) = dom ((- (id Z)) (#) cos )
by A2, A5, FDIFF_1:def 8;
then
((- cos ) - ((id Z) (#) sin )) `| Z = (- (id Z)) (#) cos
by A6, PARTFUN1:34;
hence
integral ((- (id Z)) (#) cos ),A = (((- cos ) - ((id Z) (#) sin )) . (upper_bound A)) - (((- cos ) - ((id Z) (#) sin )) . (lower_bound A))
by A1, A4, Th19, INTEGRA5:13; :: thesis: verum