Soft-Gluon Cancellation, Phases and Factorization with Initial-State   Partons
  We outline arguments for the cancellation of soft singularities in transition probabilities and parton distributions with incoming partons and Wilson lines, and with observed jets or heavy colored particles in the final states. We show the cancellation of Glauber gluons and divergent phases, relating finite remainders to corrections that arise from restrictions on final states in factorized cross sections. 
S. Mert Aybat and George Sterman