The position of the locator gives an initial point from which the simulation runs forward and backward in warped time. The lightest (benzene) and the heaviest (p-xylene) components are the unstable and stable nodes. The distillation gets richer in the heavy components until there is only p-xylene left. The intermediate component (toluene) is a saddle point. All three are extremes of the system of differential equations. If the locator is outside the triangle then the point does not correspond to a realistic mixture (i.e., it has mole fractions that are negative or greater than 1). If the user chooses a locator inside the triangle, its two coordinates correspond to the mole fractions of benzene and p-xylene (. The third (toluene’s) mole fraction is . The plot is the residue curve of the ternary mixture that represents the composition of the distillation still versus warped time.