ABSTRACT
Y. A. ABRAMOVICH Department of Mathematical Sciences, IUPUI, Indianapolis, IN 46202, USA A. K. KITOVER Department of Mathematics, CCP, Philadelphia, PA 19130, USA
INTRODUCTION
Recall that a (linear) operator T : X -> Y between vector lattices is disjointness preserving if T sends disjoint elements in X to disjoint elements in K, that is, Tx\ _L T x 2 in Y whenever jci i_ x i in X . As usual, the symbol JL denotes disjointness. The disjointness preserving operators have been studied rather intensively during the last two decades. One of the basic questions related to them is the following.
