¹²One may think of simple examples like the transition in MOSFET drain currents when going from subthreshold to strong inversion by varying the gate potential, or of the current through a series connection of a resistor and a diode, when driven by a varying voltage source. When evaluating (w_ijky_j,k-1) for large positive values of w_ijk, one indeed obtains highly nonlinear exponential “diode-like” behaviour as a function of y_j,k-1 for y_j,k-1 ≪ 0 or y_j,k-1 ≫ 0 (not counting a fixed offset of size 1 in the latter case). However, at the same time one obtains an undesirable very steep transition around y_j,k-1 = 0, approaching a discontinuity for w_ijk →∞.