User blog comment:LittlePeng9/Color reducing for Turing machines/@comment-5529393-20130413054452/@comment-1605058-20130413065507

When state has length 1 subscript, it already is onl eft end of macro cell, so we can already make transition rewrite cell. We move left, we rewrite another cell. Now we'll move, so there is only one write state. From that state we move, say, right to move state, and then to the right, but already with basic state for new machine state. So n-1 write states and n-1 move states