“…However, there are significant classes of American options, commonly traded in financial markets, whose corresponding diffusion process X is associated with Kolmogorov type operators which are not uniformly elliptic-parabolic, i.e., in particular m < N . Two such examples are provided by American Asian style options, see [1], and by American options priced in the stochastic volatility suggested in [13], see also [7] and [11]. Furthermore, as noted in [9] a general (mathematical) theory for American options in these settings is not yet available and the bulk of the literature focus mainly on numerical issues.…”