All benchmarks were performed on a 6 core (12 threads) Intel Core i7-7800X at 3.5 GHz with 64 GB of RAM. All time-critical steps of the algorithm are parallelized and we always observed near perfect scaling behavior when running the algorithm on multiple cores. The searches were performed by using parallel computation using 8 threads. Searches in the REAL Space can be performed with less than 4 GB of RAM, so it is feasible to run searches locally on standard desktop computers. We first consider six queries based on the compound G43 (a lead compound for the development of a glycosyltransferase inhibitor) that was considered in their publication (see Fig. ). In A, we search if the exact structure exists in the Enamine REAL Space and find two synthon reactions that describe this compound.