“…The existing results on GHB emerged from a corner in planar PWSs with the Jacobian matrix of each smooth subsystem having a pair of complex conjugate eigenvalues can be found in [22][23][24][25]. Under the assumption that the Jacobian matrix of each smooth subsystem is in the Jordan normal form, Akhmet [22,23] and Zou and Küpper [25] studied, respectively, the cases when the discontinuity boundaries are given by finitely many nonlinear curves and several straight lines emanating from the origin.…”