let A be closed-interval Subset of REAL ; for f being PartFunc of REAL ,REAL
for Z being open Subset of REAL st A c= Z & f = ((id Z) (#) ((sin * ln ) ^2 )) ^ & Z c= dom (cot * ln ) & Z = dom f & f | A is continuous holds
integral f,A = ((- (cot * ln )) . (upper_bound A)) - ((- (cot * ln )) . (lower_bound A))
let f be PartFunc of REAL ,REAL ; for Z being open Subset of REAL st A c= Z & f = ((id Z) (#) ((sin * ln ) ^2 )) ^ & Z c= dom (cot * ln ) & Z = dom f & f | A is continuous holds
integral f,A = ((- (cot * ln )) . (upper_bound A)) - ((- (cot * ln )) . (lower_bound A))
let Z be open Subset of REAL ; ( A c= Z & f = ((id Z) (#) ((sin * ln ) ^2 )) ^ & Z c= dom (cot * ln ) & Z = dom f & f | A is continuous implies integral f,A = ((- (cot * ln )) . (upper_bound A)) - ((- (cot * ln )) . (lower_bound A)) )
assume A1:
( A c= Z & f = ((id Z) (#) ((sin * ln ) ^2 )) ^ & Z c= dom (cot * ln ) & Z = dom f & f | A is continuous )
; integral f,A = ((- (cot * ln )) . (upper_bound A)) - ((- (cot * ln )) . (lower_bound A))
then A2:
( f is_integrable_on A & f | A is bounded )
by INTEGRA5:10, INTEGRA5:11;
A3:
- (cot * ln ) is_differentiable_on Z
by A1, Th4;
Z c= dom ((id Z) (#) ((sin * ln ) ^2 ))
by RFUNCT_1:11, A1;
then
Z c= (dom (id Z)) /\ (dom ((sin * ln ) ^2 ))
by VALUED_1:def 4;
then
Z c= dom ((sin * ln ) ^2 )
by XBOOLE_1:18;
then A6:
Z c= dom (sin * ln )
by VALUED_1:11;
B:
for x being Real st x in Z holds
f . x = 1 / (x * ((sin . (ln . x)) ^2 ))
A7:
for x being Real st x in dom ((- (cot * ln )) `| Z) holds
((- (cot * ln )) `| Z) . x = f . x
dom ((- (cot * ln )) `| Z) = dom f
by A1, A3, FDIFF_1:def 8;
then
(- (cot * ln )) `| Z = f
by A7, PARTFUN1:34;
hence
integral f,A = ((- (cot * ln )) . (upper_bound A)) - ((- (cot * ln )) . (lower_bound A))
by A1, A2, Th4, INTEGRA5:13; verum