  The factorization theorem for organizing multiple electroweak boson emissions
at future colliders with energy far above the electroweak scale is formulated.
Taking the inclusive muon-pair production in electron-positron collisions as an
example, we argue that the summation over isospins is demanded for constructing
the universal distributions of leptons and gauge bosons in an electron. These
parton distributions are shown to have the same infrared structure in the
phases of broken and unbroken electroweak symmetry, an observation consistent
with the Goldstone Equivalence Theorem. The electroweak factorization of
processes involving protons is sketched, with an emphasis on the subtlety of
the scalar distributions.
