Unary minus (multiply transfer function by -1)
function negate import ZerosAndPoles = Modelica_LinearSystems2.WorkInProgress.DiscreteZerosAndPoles; input ZerosAndPoles zp; output ZerosAndPoles result(n1 = zp.n1, n2 = zp.n2, d1 = zp.d1, d2 = zp.d2, k = -zp.k) "= -zp"; end negate;