The Assigner itself performs three operations: Get Class, Get Mechanism, and Get Head Tail. The operations define the polymer class, the polymerization mechanism, and head and tail positions. For identifying the polymer class, the monomer SMILES is compared with the SMARTS of the most common functional groups that define a polymer class. For example, polyamide contains two functional groups: amide and carboxilic acid. If one of the groups is detected as a nucleophilic site, the molecule is classified as a polyamide.