“…, k} exists with w∈N (u) c(uw) = w∈N (v) c(vw) for every u, v ∈ V , u = v. This graph invariant has been analyzed in multiple papers, see e.g. [3,7,12,13,14,16,19,22,26,28,33], but also gave rise to a fast-developing branch of research, which may be referred to as "additive graph labellings", or more generally "vertex distinguishing colourings", see [1,2,6,8,9,15,20,29,35,36,37] for examples of papers introducing a few representative concepts of this branch. One of these is a problem of a total neighbour sum distinguishing colouring of a given graph graph G = (V, E), i.e.…”