Gauge invariant YFS exponentiation of (un)stable W$^{+}$W$^{-}$ production at and beyond LEP2 energies

We present the theoretical basis and sample Monte Carlo data for the YFS exponentiated calculation of e^+e^- \rightarrow W^+ W^- \rightarrow f_1\bar f'_1 + \bar f_2 f'_2 at and beyond LEP2 energies, where the left-handed parts of f_i and f'_i are the respective upper and lower components of an SU_{2L} doublet, i=1,2. The problem of gauge invariance of the radiation from the unstable charged spin~1 W^{\pm} is solved in an entirely physical manner. Our formulas are illustrated in a proto-typical YFS Monte Carlo event generator YFSWW2, wherein both Standard Model and anomalous triple gauge boson couplings are allowed.