Finally,differentPOscanbecombinedusingrelations(RLs). EveryRLlinksatleasttwoparticipants(POs),which are connected one to another by mutual dependencies related to some DPs or OPs that determine presentable effects oftheRL,e.g.,arelationthatdeterminestherelativepositionofsomePOslinksthesePOsandspecifiestheirrelative orientations and distances between them. RLs that link two POs may be encoded using OPs (binary RLs), while RLs that link more than two POs are encoded using individuals that link the POs by OPs (n-ary RLs).