A closely related model, the Erdős–Rényi model denoted "G"("n","M"), assigns equal probability to all graphs with exactly "M" edges. With 0 ≤ "M" ≤ "N", "G"("n","M") has formula_3 elements and every element occurs with probability formula_4. The latter model can be viewed as a snapshot at a particular time ("M") of the random graph process formula_5, which is a stochastic process that starts with "n" vertices and no edges, and at each step adds one new edge chosen uniformly from the set of missing edges.