Previously, component-wise relative error bound was tested.  However,such bound can't exist already for complex multiplication as one can beused to perform subtraction of floating-point numbers, e.g. x and y forz0=1+1j and z1=x+yj.```pycon>>> x, y = 1e-9+1j, 1+1j>>> a = x*y*y.conjugate()/2;a(1.0000000272292198e-09+1j)>>> b = x*(y*y.conjugate()/2);b(1e-09+1j)>>> b == xTrue>>> (a.real-b.real)/math.ulp(b.real)131672427.0```