r, Z, t, r2, d3, d4, 
(-d3^3*d4+d3^2*d4^2-d3*d4^3-d3*d4*r2^2+d3*d4*r+d3*d4+r2^2+Z-r)*t^4+(2*d3^2*d4*r2-4*d3*d4^2*r2+2*d4^3*r2+2*d4*r2^3-2*d4*r*r2+2*d4*r2)*t^3-(-2*d3^2*d4^2+4*d4^2*r2^2+4*d4^2+2*r2^2+2*Z-2*r)*t^2+(2*d3^2*d4*r2+4*d3*d4^2*r2+2*d4^3*r2+2*d4*r2^3-2*d4*r*r2+2*d4*r2)*t+r2^2+d4^3*d3-d4*d3*r+d4*d3*r2^2+Z-r-d4*d3+d4^2*d3^2+d4*d3^3
