  The forward-backward asymmetry of the Drell-Yan process in dilepton decays at
high invariant masses can be used to probe the parton distribution functions at
large x. The behavior of three modern PDF sets (CT18NNLO, MSHT20, and NNPDF4.0)
are compared, and updated under various scenarios via ePump using proton-proton
collision pseudo-data generated at sqrt(s) = 13 TeV with 3000 fb^{-1} of
integrated luminosity.
