A Structure Theory for Small Sum Subsets

We develop a new method leading the structure of finite subsets S and T of an abelian group with $\mathrm{\mid }S+T\mathrm{\mid }\le \mathrm{\mid }S\mathrm{\mid }+\mathrm{\mid }T\mathrm{\mid }$. We show also how to recover the known results in this area in a relatively short space.