generators.ET0LTreeGrammar:
( { S, A, D },
  { F:1, star:0, G:4, -:0, S:0, A:0, D:0 },
  { 
    {
      A -> G[S,D,D,S],
      D -> A,
      S -> F[S]
    },
    { % table replication - just a dirty trick to choose it twice as often
      A -> G[S,D,D,S],
      D -> A,
      S -> F[S]
    },
    {
      A -> G[S,-,D,S],
      D -> A,
      S -> F[S]
    },
    {
      A -> G[S,D,-,S],
      D -> A,
      S -> F[S]
    }
  },
  G[S,D,D,S] )
