Summary

• it is hard to read the de Bruijn diagrams. There is a graphing thesis. It needs to be interconnected to the NXLCAU programs.

• preparing the section of Rule 110 made it completely clear that Rule 110 is an exercise in tiling the plane with integer right triangles. They are something like polyominoes [89] except that the goal is not to cover the plane with certain objects of fixed area. Rather, the shape is fixed, the area variable, and a supplementary condition that top edges never continue one another. To do this, T0 triangles should be introduced, and diagonal cells should be withdrawn for all the others.

• the Faddeev computacion of the characteristic polynomial ought to go into the ``ancestors'' menu of the NXLCAU programs.