  We consider a system of linear equations, whose coefficients depend linearly
on interval parameters. Its solution set is defined as the set of all solutions
of all admissible realizations of the parameters. We study unbounded directions
of the solution set and its relation with its kernel. The kernel of a matrix
characterizes unbounded direction in the real case and in the case of ordinary
interval systems. In the general parametric case, however, this is not
completely true. There is still a close relation preserved, which we discuss in
the paper. Nevertheless, we identify several special sub-classes, for which the
characterization remains valid. Next, we extend the results to the so called AE
parametric systems, which are defined by forall-exists quantification.
