  In this paper we give a subdirect decomposition of semigroups $({\mathfrak
F}(S); \circ )$, where $S$ is a semigroup, ${\mathfrak F}(S)$ is the set of all
fuzzy sets in $S$, and the operation $\circ$ on ${\mathfrak F}(S)$ is defined
by the following way: for $f, g\in {\mathfrak F}(S)$ and $s\in S$, $(f\circ
g)(s)=\vee _{{x, y\in S}\atop{s=xy}}(f(x)\wedge g(y))$ if $s\in S^2$, and
$(f\circ g)(s)=0$ otherwise.
