“…Recently, DG methods have been applied for solving VIs, such as gradient plasticity problem [27,28], obstacle problems [29,30], Signorini problem [31,32], quasistatic contact problems [33], plate contact problem [34][35][36], two membranes problem [37] and Stokes or Navier-Stokes flows with slip boundary condition [38,39]. A posteriori error analysis of DG methods for VIs was also considered in [40][41][42][43][44].…”