x12-y12
/\
(x6-y6)(x6+y6)
/ \ / \
(x3-y3)(x3+y3)(x2+y2)(y4+x2y2+y4)
/ \ / \
(x+y)(x2-xy+y2)(x-y)(x2+xy+y2)
(x+y)(x2-xy+y2)(x-y)(x2+xy+y2)(x2+y2)(y4-x2y2+y4)
Edwin