Higher Order Heavy Quark Corrections to Deep-Inelastic Scattering

The 3-loop heavy flavor corrections to deep-inelastic scattering are essential for consistent next-to-next-to-leading order QCD analyses. We report on the present status of the calculation of these corrections at large virtualities $Q^2$. We also describe a series of mathematical, computer-algebraic and combinatorial methods and special function spaces, needed to perform these calculations. Finally, we briefly discuss the status of measuring ${\alpha }_s(M_Z)$, the charm quark mass $m_c$, and the parton distribution functions at next-to-next-to-leading order from the world precision data on deep-inelastic scattering.