SANCnews: Top decays in QCD and EW sectors

In this paper we present the results of the implementation of the decay t → bf ₁ $ bar f $ bar f ′₁ into the SANC system (f ₁ is a massless fermion). The new aspect of the work is the combination of QCD and EW corrections. All calculations are done at the one-loop level in the Standard Model. We give a detailed account of the new procedure — the forming of a class of J _{AW, WA} functions. These functions are related to the procedure of extraction of infrared and mass-shell singular divergences. The emphasis of this paper is on the presentation of numerical results for various approaches: complete one-loop calculations and different versions of pole approximations.