“…In 1969, Wielandt initiated the study of 2-closures of permutation groups to present a unified treatment of finite and infinite permutation groups, based on invariant relations and invariant functions [22]. After Wielandt's pioneering work, there was some progress on the subject achieved mostly in the case of primitive groups [12,13,16,19,20,25] and the 2-closure was used as a tool in studying the graph isomorphism problem [9,17,18]; the isomorphism problem for Schurian coherent configurations [10,21]; and in the study of automorphisms of vertex transitive graphs [7,23,24]. The latter of these led to the formulation of the Polycirculant conjecture [5], which remains open, and has garnered much recent attention [2].…”