  The two loop equal mass sunrise graph is considered in the continuous
d-dimensional regularisation for arbitrary values of the momentum transfer.
After recalling the equivalence of the expansions at d=2 and d=4, the second
order differential equation for the scalar Master Integral is expanded in (d-2)
and solved by the variation of the constants method of Euler up to first order
in (d-2) included. That requires the knowledge of the two independent solutions
of the associated homogeneous equation, which are found to be related to the
complete elliptic integrals of the first kind of suitable arguments. The
behaviour and expansions of all the solutions at all the singular points of the
equation are exhaustively discussed and written down explicitly.
