As seen in the Figure , ≥ 83% of routes without multiproduct reactions at reaction steps 2 and 3 are extensions of previous reaction step routes. The remaining bulk are identical routes (no extensions were found), and there exists a small fraction of routes that are classified as not found due to a cycle being detected in the route. As explained below, such routes are not synthetically meaningful and are the consequence of the use of artificial inventory information. Nevertheless, the ratio of rejected routes was consistently minimal in the case of -/-database configuration across the experiments.