Features: Generate a primary library of global and local pairwise alignments For each pair of residue matches assign a weight depending on the identity of both sequences Combination of information: merge duplicated pairs in the library adding their weights (signal addition) Extended library: individual alignment of each pair of sequences with the rest of sequences to provide more consistency to residue matches appearing in more than one pairwise alignment (triplet approach). Progressive alignment: neighbour-joining method. The matrix of substitutions will be the extended library. No gap penalties.