The results show that the training of production based aggregation method is easier than the summation based method. So in the following experiments, only production scoring models were discussed. During RL, all generated PROTACs will be saved as potential solutions for later inspection. We analyzed the number of molecules in the collection under different constraints of linker length and the result are shown in Figure . In this case, during the RL run, only constraint of link length were varied and all other parameters were the same. In Figure , if no constraint of link length was imposed, the link length of generated solutions covers a very wide range (2~35), while adding constraint on linker length, the linker length of generated solutions is in the range of 5~15. As the range of constraint of link length becomes wider, the distribution of linker length of collected solutions also become wider, although it is not dramatically. This suggested that in RL framework, the restraining of link length does work. The effect of RL was also examined by looking at ratio of compounds which have good scores as shown in Table . As a comparison, without running RL, we randomly sampled the prior model (ie. the model from Link-INVENT) to generate 20K