 Beishui Liao and his collaborators (Liao et al. 2011) addressed the issue of the computational dynamics of argument systems by investigating under which conditions an argument system can be divided into modules, so that the implications of new information can be efficiently computed by updating only the affected module. They discovered that such modularity is possible for any semantics that has the property of directionality. A semantics is directional if and only if, for every argument structure AS, the intersection of any extension prescribed for AS with an unattacked set /(U/) is identical to one of the extensions prescribed for the restriction of AS to \(U\), and vice versa. See also Baroni et al. 2018.