Start
  p
    Nodes[Nt]
      t_0
        l@(1:1-1:3)='ab'
      t_1
        a@(1:3-1:4)='a'
      t_0
        l@(1:4-1:6)='ab'
      t_1
        a@(1:6-1:7)='a'
  Eof@(2:1-2:1)=''