  A large class of Feynman integrals, like e.g., two-point parameter integrals
with at most one mass and containing local operator insertions, can be
transformed to multi-sums over hypergeometric expressions. In this survey
article we present a difference field approach for symbolic summation that
enables one to simplify such definite nested sums to indefinite nested sums. In
particular, the simplification is given -if possible- in terms of harmonic
sums, generalized harmonic sums, cyclotomic harmonic sums or binomial sums.
Special emphasis is put on the developed packages Sigma, EvaluateMultiSums and
SumProduction that assist in the task to perform these simplifications
completely automatically for huge input expressions.
