Figure 4. Correspondence matrices and matrix patterns.

Two positions are represented by two residues each. MSTs for these residues are represented by triangles with the associated residue indicated in the center. A. Coupling pattern with an identity correspondence matrix. B. Multi-inclusion pattern where a single residue at position i is associated to several residues at j. C. Multi-overlapping pattern where several residues at i are associated to several residues at j.