Two stage binary matrix
Not every node of a two stage diagram or beyond links to all the other nodes; their topological matrices present the form of a series of staircases, corresponding to the diagram shown in Figure 7.
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Simple calculation reveals that the minimal equation is 
with eigenvalues 2, 0, 0, and principal vectors
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given that one of the zero eigenvalues has a 
Jordan block.
Harold V. McIntosh
E-mail:mcintosh@servidor.unam.mx