
 Improper integral (Site not responding. Last check: 20071013) 
  In calculus, an improper integral is the limit of a definite integral, as an endpoint,or both endpoints, of the interval approaches either a specified real number or ∞ or −∞. 
  By using the more advanced Lebesgue integral, rather than the Riemannintegral, one can in some cases bypass this requirement, but if one simply wants to evaluate the limit to a definite answer,that technical fix may not necessarily help. 
  It is more or less essential in the theoretical treatment for the Fourier transform, with pervasive use of integrals over the whole realline. 
 www.therfcc.org /improperintegral85892.html (353 words) 
