example8 := (53+95*x^2-14*x*y+61*x+83*y^2-83*y)/(-88-6*x^2+52*x*y-40*x+45*y^2-\ 86*y)*((-21*x+28*y+92)/(35*x-31*y-17))^(1/2)*exp((-37+17*x^2+31*x*y-52*x+44*y^ 2-16*y)/(-15-59*x^2-47*x*y+58*x-56*y^2-45*y));