 We wouldn’t exhibit the right sort of cooperative attitude for shared activity and intention if the mesh of our sub-plans were accidental and we were not at all disposed to make them consistent if they were to become incompatible. That’s why Bratman requires the intention to mesh  subplans.[17]  There is, moreover, a normative element to the meshing, as emphasized by Roth 2003. Participants are subject to some sort of rational  requirement[18]  such that they in a sense ought to mesh their plans: the plans of the other participants serve as a normative constraint on one’s own plans. And there is no reason to restrict this status to the plans, and not extend it to the intentions that generate them. Thus, shared activity exhibits what Roth calls practical intersubjectivity. In effect, each participant treats the other’s intentions and plans much in the way that he or she treats her own: as rational constraints on further intention and planning.