Linking more than two fragments F together given a single specified attachment point A F requires slightly more prompt engineering. For each fragment after the initial prompt fragment, the molecule is scanned and a fragment is inserted at each linker atom and the likelihood of the sequence being generated by the CLM is assessed. Such that the insertion point is selected to result in the sequence likelihood. Further fragments are inhibited from insertion at the indexes of a previous fragment. The algorithm for this is shown in Algorithm 3. One caveat to this approach is that during RL the model may learn to generate the desired fragment before insertion, therefore, we implemented a simple check to skip fragment insertion if it already exists to help limit repeated fragments if they occur.