Factorizations of Linear Relations
  Given two linear relations $A$ and $B$ we characterize the existence of a linear relation (operator) $C$ such that $A\subseteq BC$, respectively $A\subseteq CB.$ These factorizations extend and improve well-known results by R.G. Douglas and Z. Sebesty\'en. 
Dan Popovici and Zoltan Sebestyen
math.FA