let A be closed-interval Subset of REAL ; :: thesis: for f being PartFunc of REAL ,REAL
for Z being open Subset of REAL st A c= Z & f = ((id Z) (#) ((cos * ln ) ^2 )) ^ & Z c= dom (tan * ln ) & Z = dom f & f | A is continuous holds
integral f,A = ((tan * ln ) . (upper_bound A)) - ((tan * ln ) . (lower_bound A))
let f be PartFunc of REAL ,REAL ; :: thesis: for Z being open Subset of REAL st A c= Z & f = ((id Z) (#) ((cos * ln ) ^2 )) ^ & Z c= dom (tan * ln ) & Z = dom f & f | A is continuous holds
integral f,A = ((tan * ln ) . (upper_bound A)) - ((tan * ln ) . (lower_bound A))
let Z be open Subset of REAL ; :: thesis: ( A c= Z & f = ((id Z) (#) ((cos * ln ) ^2 )) ^ & Z c= dom (tan * ln ) & Z = dom f & f | A is continuous implies integral f,A = ((tan * ln ) . (upper_bound A)) - ((tan * ln ) . (lower_bound A)) )
assume A1: ( A c= Z & f = ((id Z) (#) ((cos * ln ) ^2 )) ^ & Z c= dom (tan * ln ) & Z = dom f & f | A is continuous ) ; :: thesis: integral f,A = ((tan * ln ) . (upper_bound A)) - ((tan * ln ) . (lower_bound A))
then A2: ( f is_integrable_on A & f | A is bounded ) by INTEGRA5:10, INTEGRA5:11;
A3: tan * ln is_differentiable_on Z by A1, FDIFF_8:14;
Z c= dom ((id Z) (#) ((cos * ln ) ^2 )) by RFUNCT_1:11, A1;
then Z c= (dom (id Z)) /\ (dom ((cos * ln ) ^2 )) by VALUED_1:def 4;
then Z c= dom ((cos * ln ) ^2 ) by XBOOLE_1:18;
then A6: Z c= dom (cos * ln ) by VALUED_1:11;
B: for x being Real st x in Z holds
f . x = 1 / (x * ((cos . (ln . x)) ^2 ))

proof

let x be Real; :: thesis: ( x in Z implies f . x = 1 / (x * ((cos . (ln . x)) ^2 )) )
assume C: x in Z ; :: thesis: f . x = 1 / (x * ((cos . (ln . x)) ^2 ))
then (((id Z) (#) ((cos * ln ) ^2 )) ^ ) . x = 1 / (((id Z) (#) ((cos * ln ) ^2 )) . x) by RFUNCT_1:def 8, A1
.= 1 / (((id Z) . x) * (((cos * ln ) ^2 ) . x)) by VALUED_1:5
.= 1 / (x * (((cos * ln ) ^2 ) . x)) by FUNCT_1:35, C
.= 1 / (x * (((cos * ln ) . x) ^2 )) by VALUED_1:11
.= 1 / (x * ((cos . (ln . x)) ^2 )) by A6, FUNCT_1:22, C ;
hence f . x = 1 / (x * ((cos . (ln . x)) ^2 )) by A1; :: thesis: verum

end;

A7: for x being Real st x in dom ((tan * ln ) `| Z) holds
((tan * ln ) `| Z) . x = f . x

proof

let x be Real; :: thesis: ( x in dom ((tan * ln ) `| Z) implies ((tan * ln ) `| Z) . x = f . x )
assume x in dom ((tan * ln ) `| Z) ; :: thesis: ((tan * ln ) `| Z) . x = f . x
then A8: x in Z by A3, FDIFF_1:def 8;
then ((tan * ln ) `| Z) . x = 1 / (x * ((cos . (ln . x)) ^2 )) by A1, FDIFF_8:14
.= f . x by B, A8 ;
hence ((tan * ln ) `| Z) . x = f . x ; :: thesis: verum

end;

dom ((tan * ln ) `| Z) = dom f by A1, A3, FDIFF_1:def 8;
then (tan * ln ) `| Z = f by A7, PARTFUN1:34;
hence integral f,A = ((tan * ln ) . (upper_bound A)) - ((tan * ln ) . (lower_bound A)) by A1, A2, FDIFF_8:14, INTEGRA5:13; :: thesis: verum