\magnification=1200
\hsize=4in
\overfullrule=0pt
\input amssym
%\def\frac#1 #2 {{#1\over #2}}
\def\emph#1{{\it #1}}
\def\em{\it}
\nopagenumbers
\noindent
%
%
{\bf Pingzhi Yuan }
%
%
\medskip
\noindent
%
%
{\bf Subsequence Sums of Zero-sum-free Sequences}
%
%
\vskip 5mm
\noindent
%
%
%
%
Let $G$ be a finite abelian group, and let $S$ be a sequence of
elements in $G$. Let $f(S)$ denote the number of elements in $G$ which
can be expressed as the sum over a nonempty subsequence of $S$. In
this paper, we slightly improve some results of Pixton on $f(S)$
and we show that for every zero-sum-free sequences $S$ over $G$ of
length $|S|=\exp(G)+2$ satisfying $f(S)\geq 4\exp(G)-1$.



\bye
