  This paper describes applications of extrapolation for the computation of
coefficients in an expansion of infrared divergent integrals. An extrapolation
procedure is performed with respect to a parameter introduced by dimensional
regularization. While this treats typical IR singularities at the boundaries of
the integration domain, special care needs to be taken in cases where the
integrand is singular in the interior of the domain as well as on the
boundaries. A double extrapolation is devised for a class of massless vertex
integrals. Quadruple precision results are presented, demonstrating high
accuracy. The computations are supported by the use of general adaptive
integration programs from the QUADPACK package, in iterated integrations with
highly singular integrand functions.
