“…Herein, we consider the 5-D linear system given in [2, Equation 3.11, p. 39], with [0, T ] = [0, 2], and under-approximate the reachable tube R([0, T ]) using the proposed method with two values of the discretization parameter N (N ∈ {10, 100}), where we set ǫ h = 1−1/N 3 and ǫu = 1−1/N 2 . As the exact reachable tube is not known, we use the convergent over-approximation method of Serry and Reissig [16], with a refined time discretization (400 steps) and an accurate approximation of the matrix exponential (L(•, 10)) to produce an accurate representation of the reachable tube and compare it with the computed under-approximations from the proposed method. Figure 2 displays two projections of the over-approximation and the under-approximations.…”