Unsigned Addition Forms an Abelian Group o is additive identity UAddw u,o) Every element has additive inverse Let UCompw(u)=2w-u P68(2.10) UAddw(u, UCompw(u))=07 Unsigned Addition Forms an Abelian Group • 0 is additive identity – UAddw (u , 0) = u • Every element has additive inverse – Let UCompw (u ) = 2 w – u – UAddw(u , UCompw (u )) = 0 P68 （2.10）