“…The problem of determining the existence of a reachable path for (2) has eluded researchers for a long time, and, to the best of our knowledge, the only efforts in studying the existence of reachable paths for (2) can be found in [2], [3], [4], [5], [6]. First, in a series of papers [2], [3], [6], Stanford and Conner studied the structure of the reachable set of switched linear systems, and showed that it was a subspace of R n in reversible (i.e., with invertible A(θ k ) matrices) systems [6], and, in general, a union of arbitrarily many maximal subspaces in [3].…”