  We present the key features relevant to the automated computation of all the
leading- and next-to-leading order contributions to short-distance cross
sections in a mixed-coupling expansion, with special emphasis on the first
subleading NLO term in the QCD+EW scenario, commonly referred to as NLO EW
corrections. We discuss, in particular, the FKS subtraction in the context of a
mixed-coupling expansion; the extension of the FKS subtraction to processes
that include final-state tagged particles, defined by means of fragmentation
functions; and some properties of the complex mass scheme. We combine the
present paper with the release of a new version of MadGraph5_aMC@NLO, capable
of dealing with mixed-coupling expansions. We use the code to obtain
illustrative inclusive and differential results for the 13-TeV LHC.
