Abstract
A deterministic system theory is developed for two-point boundary-value descriptor systems (TPBVDSs). In particular, detailed characterizations of the properties of reachability, observability and minimality are obtained. In addition, extendibility, i.e. the concept of considering TPBVDS as being defined on a sequence of intervals of increasing length, is defined and studied. This system theory generalizes our earlier results for the class of stationary systems for which the input-output map (weighting pattern) is shift-invariant.