Bicommutants and Arens regularity

Bojan Magajna

Let $C$ and $R$ be unital rings and $Z$ an injective cogenerator for right $C$-modules. For an $R,C$-bimodule $U$ let $U^{\ast }=Ho{m}_C(U,Z)$, $S=En{d}_R(U)$ and $Bien{d}_R(U)=En{d}_S(U)$, the…