Unary minus (multiply zeros and poles description by -1)
function negate import Modelica_LinearSystems2.ZerosAndPoles; input ZerosAndPoles zp "Zeros-and-poles data record"; output ZerosAndPoles result(n1 = zp.n1, n2 = zp.n2, d1 = zp.d1, d2 = zp.d2, k = -zp.k) "= -zp"; end negate;