The main goal of this paper is to show that a
-arc in
and
is subset of a twisted cubic, that is, a normal rational curve. The maximum size of an arc in a projective space or equivalently the maximum length of a maximum distance separable linear code are classified. It is then shown that this maximum is
for all dimensions up to
.
Let R be a commutative ring with unity and an R-submodule N is called semimaximal if and only if
the sufficient conditions of F-submodules to be semimaximal .Also the concepts of (simple , semisimple) F- submodules and quotient F- modules are introduced and given some properties .