rise to a collinear singularity, one should only consider pairs arising from the same resonance decay, or directly from the production process.

In the framework, a subtraction method that preserves the resonance masses is already implemented, but it is presently available only for calculations performed in the zero width approximation. In these cases, only one resonance decay chain is possible, and the real emission contributions are separated according to the resonance that originates the radiation. The method is discussed in detail in ref. [[@Campbell:2014kua]]{}. In essence, with this method, the subtraction procedure for initial state radiation is the same one used in ref. [[@Frixione:2007vw]]{} (the FNO paper from now on). For final state radiation arising from the production process the subtraction procedure is also the same one discussed in Section 5.2 of FNO. This procedure is such that the mapping of the real to the underlying Born configuration does not change the four momentum of the final state. In case of radiation from the decay of a resonance, the subtraction procedure is essentially the same, except that it is applied in the resonance frame, and thus does not alter the resonance four momentum and the momenta of all particles that 