The synthesis route shown in Figure is a viable synthesis route identified at search depth of 2 reaction steps, as it can be performed from readily available starting materials in a self-contained manner. Increasing the search depth to 3 reaction steps, we identified that the cycle was introduced into the synthesis route, rendering it non-viable, therefore rejected (see Figure ). How is this possible? The explanation is that this is an artifact introduced by the use of artificial inventory status. One can observe that substance YEWFMQPTEIBRFH-UHFFFAOYSA-N is a starting material in Figure . However, the increased search depth identified a reaction (ASPR 1001638987) of which the same substance is a product of. Furthermore, an intermediate substance PBBCMQAOJDGANI-UHFFFAOYSA-N of the original synthesis route is a reactant of the same reaction in question at search depth of 3 reaction steps. This constitutes a circular dependency, as neither YEWFMQPTEIBRFH-UHFFFAOYSA-N nor PBBCMQAOJDGANI-UHFFFAOYSA-N are starting materials in the synthesis route of Figure . Therefore, the synthesis route is correctly rejected.