p502fig13.27 Despite the fact that less transmitter y is available after persistent activation by a larger input signal S, the gated output signal S*y is larger die to the mass action gating of S by y.<BR>||  Minor mathematical miracle.  At equilibrium: 0 = d[dt: y] = A*(B - y) - S*y.  Transmitter y decreases when input S increases: y = A*B/(A + S).  However, output S*y increases with S!:  S*y = S*A*B/(A + S) (gate, mass action).