(x^2-2)*(x^4+2*x^2+4)-(x^3-1)^2
x^6+2*x^4+4*x^2-2*x^4-4*x^2-8-(x^6-2*x^3+1)
x^6+2*x^4+4*x^2-2*x^4-4*x^2-8-x^6+2*x^3-1
-9+2*x^3
(m^2-1)*(m^4+m^2+1)-(m^2-1)^3
m^6+m^4+m^2-m^4-m^2-1-(m^6-3*m^4*1+3*m^2*1-1)
m^6+m^4+m^2-m^4-m^2-1-m^6+3*m^4*1-3*m^2*1+1
3*m^4-3*m^2