Two-loop Fermionic Electroweak Corrections to the Effective Leptonic   Weak Mixing Angle in the Standard Model
  We give some details of the recently completed calculation of the full two-loop fermionic corrections to the effective leptonic weak mixing angle. Among others, we describe the C++ library DiaGen/IdSolver, which was used to reduce the two-loop light fermion vertex diagrams to linear combinations of master integrals with rational function coefficients. 
M. Awramik (DESY, Zeuthen & HNINP, Cracow), M. Czakon (DESY, Zeuthen &   Silesia U.), A. Freitas (Fermilab), G. Weiglein (Du...