theorem :: INTEGR14:19

for A being non empty closed_interval Subset of REAL
for f being PartFunc of REAL,REAL
for Z being open Subset of REAL st A c= Z & ( for x being Real st x in Z holds
f . x = (sin . (ln . x)) / (x * ((cos . (ln . x)) ^2)) ) & Z c= dom (sec * ln) & Z = dom f & f | A is continuous holds
integral (f,A) = ((sec * ln) . (upper_bound A)) - ((sec * ln) . (lower_bound A))