Data:L10a168/Multivariable Alexander

[math]\displaystyle{ v u^3+w u^3-u^3-3 v u^2+2 v w u^2-3 w u^2+2 v x u^2-v w x u^2+2 w x u^2-2 x u^2+2 u^2+2 v u-2 v w u+2 w u-3 v x u+2 v w x u-3 w x u+2 x u-u+v x-v w x+w x }[/math]