“…Discounted optimal stopping problems for the running maxima and minima of the initial continuous (diffusion-type) processes were initiated by Shepp and Shiryaev [44] and further developed by Pedersen [36], Guo and Shepp [24], Gapeev [14], Guo and Zervos [25], Peskir [39,40], Glover, Hulley, and Peskir [22], Gapeev and Rodosthenous [17][18][19], Rodosthenous and Zervos [43], Gapeev, Kort, and Lavrutich [20], and Gapeev and Al Motairi [15] among others. It was shown, by means of the maximality principle for solutions of optimal stopping stopping problems established by Peskir [37], which is equivalent to the superharmonic characterization of the value functions, that the optimal stopping boundaries are given by the appropriate extremal solutions of certain (systems of) first-order nonlinear ordinary differential equations.…”