Forme Equivalente \`a la Condition $\Delta_2 $ et Certains r\'esultats   de s\'eparations dans les Espaces Modulaires
  In this paper, we present an equivalent form of the $\Delta_2 $-condition which allow us to redefine the topological vector space structure of a modular spaces using the filter base. We show also the characterization of closed subsets (in the sens of this topology) of a modular spaces which permit us to establish some separation results in modular spaces 
A.Hajji