Figure 31: Cook's A-gliders and the de Bruijn
diagram from which they may be derived. The outer periphery corresponds to the
period-7, cycle 14 period rectangle of the ether tiles. If T3's and T1's
alternate, there are three phases each of which has a cycle length of 6.
Also, if pure T1's run in succession, there is a loop of length 4 which
will geberate them. Other mixtures correspond to other paths through the
diagram.